please rephrase the next paragraph in a formal academic templet " Of all the gynecologic cancers, only cervical cancer has a screening test. Cervical Pap smear is the best screening method for cervical precancerous lesions and is best reported using a unified and a well-established reporting system like Bethesda System. In this system, squamous intraepithelial lesion (SIL) includes a spectrum of squamous cell lesions starting from the precancerous lesions of low-grade SIL (LSIL) to high-grade SIL (HSIL), and eventually invasive squamous cell carcinoma (Alrajjal et al., 2021).
Cervical cancer is the only malignant tumor in the world with well-established causes and preventative treatments. However, CIN I brought on by widespread HPV infection typically goes away on its own and doesn't require any more care. Some CIN I, however, will develop into CIN II or CIN III and eventually become squamous cell carcinoma (Wang et al., 2018). 
The average age of the participants of this current study ranged from 44 to 71 years with a mean (58.2±9.01 years). The association between age and various instances was statistically insignificant (P-value 0.351). These findings are consistent with Pandey et al., 2018 who reported that the mean age of total cases was 48.28 ± 8.9 years with a range of 30–61 years. Our results are also in near with the result of Hu et al., 2019 who reported that their patients aged from 20 to 71 years (mean 40.6 years). According to Chaloob et al., 2016 the average age of LSIL cases ranged from 22 to 62 years with a mean (38.46±2.3 years), while the average age of HSIL cases ranged from 27 to 63 years with a mean (43.32±1.92 years).
Regarding the grade of squamous intraepithelial lesions; the cases of LSIL (21 cases) were higher than the cases of HSIL (4 casers only). This finding is in agreement with Hu et al., 2019 who reported that their patients with LSIL were 380, while HSIL were 267 cases. Also Pandey et al., 2018 reported that cases with LSIL were 16 and HSIL were only 3 cases. While this result different from that reported by Chaloob et al., 2016 who reported that their patients with LSIL were 24, while HSIL were 28 patients. Our finding differs also from that reported by Zhang et al., 2014 who reported that their cases with LSIL were 18, while HSIL were 33 cases. 
Cervical cancer screening tests that use conventional cytology have demonstrated obvious reductions in both cervical cancer morbidity and mortality in the past decades. However, conventional cytology lacks enough sensitivity and specificity.  Then histology screening tests were suggested, but various points in the histological diagnosis of cervical biopsy specimens are still a potential problem (Hu et al., 2019). 
Improving screening tests is a priority task for the early diagnosis of cervical lesion. Moreover, the current screening tests for cervical cancer like histology and cytology are unable to distinguish the lesions which have high risk progressing to HSIL (Cuzick, 2010).
Many researches have carried out on finding possible specific biomarkers in cervical lesions. In this work, we detected expression of P15 & P16 in different biopsies of normal tissue as well as premalignant lesions of cervix, by immunohistochemistry to explore the possibility of P15 and P16 as diagnostic and prognostic markers in cervical lesions, also to clarify their role in carcinogenesis and progression of cervical cancer.
P15 belongs to a family of cyclin dependent kinase inhibitors that negatively regulate the cell cycle through inhibition of the cyclin dependent kinase 4 and 6 involved in cell cycle regulation (Banerjee et al., 2020).
In our current study, ratio of high expression of P15 showed statistically significant stepwise increase from NIL (0.0%) to LSIL (33.3%) to HSIL (50.0%) with a P-value of 0.003. These findings are in line with Zhang et al., 2014 who reported that the ratio of high P15 expression in CIN3 and CIN2 (100.0%, & 62.5% respectively) was highly significant increased than that in CIN1 and normal cervix (0.0% for both) with a P-value of 0.000. Feng et al., 2007 also reported that the strong positive rate for P15 expression in CIN and normal cervix was (30.0% & 0.0%), respectively. These results elucidated that P15 expression increased in higher histological grade. 
P16 is a cyclin-dependent kinase inhibitor that blocks the phosphorylation of various cyclins. When HPV infects cervical cells, HPV produces E7, the E7 proteins bind and inactivate the tumor-suppressor function of the pRb. P16 overexpression occurs as a negative feedback mechanism for the inactivation of pRb in dysplastic cervical cells Zheng et al., 2016. 
Our study demonstrates that the ratio of high P16 expression showed statistically significant stepwise increase from NIL (12.0%) to LSIL (52.4%) to HSIL (75.0%) with a P-value of 0.003. This is in accordance with the result of Zhang et al., 2014 who discovered a significant increase in high P16 expression from normal cervix (31.6%) to CIN1 (55.6%) through CIN2 (62.5%) to CIN3 (88.2%) with a P-value 0.004.
 Furthermore, Hu et al., 2019 reported that the ratio of the positive rates of P16 in normal cervix, LSIL, HSIL and invasive cancer were 33.3%, 75.0%, 96.3% and 100%, respectively. In addition, Hu et al., 2019 also found that with the severity of the cervical lesion, the intensity of positive expression of P16 increased and the ratio of the strong positive rates of P16 in Normal, LSIL, HSIL and invasive cancer were 0.0%, 10.7%, 92.6% and 100.0%, respectively with a P-value of 0.00. 
Kishore & Patil, 2017 demonstrated that the P16 expression was absent in normal cervical epithelium in all cases and it increased from 25% positive cases in CIN 1 to 75% cases of CIN 3 showing positivity. On semi-quantitative scoring, overexpression for P16 was observed in 25% of CIN 1 cases, 50% of CIN 2 and 75% of CIN 3 cases. All cases of carcinoma cervix were positive for P16 expression with P-value < 0.05. 
According to a study by Pandey et al., 2018 P16 was positive in 96% of invasive cervical cancer, 66.6% in HSIL, and 37.5% in LSIL, while it was negative in all the non-neoplastic controls. Chaloob et al., 2016 also discovered a highly significant increase in the IHC expression of P16 from LSIL (37.5%) through HSIL (67.9%) to carcinomas (94.3%), (P˂0.001), No one of the cases of chronic cervicitis showed positive immunoreactivity to P16.
This study reported that there was no a significant relation between P15, P16 expression and age of patients with a P-value (0.625 & 0.228, respectively).  This is in accordance with the results of Chaloob et al., 2016 who reported non-significant association of P16 expression with age of patients in SILs with a P-value 0.378. Our study demonstrated a highly significant direct relation between P15 and P16 expression in different studied cases with a P-value <0.0001.
In conclusion, the current study proved a positive correlation between P15 and P16 expression with degree of the cervical neoplasia, which was consistent with other researches. This suggests that P15 and P16 immuno-expression increases with the severity of cervical lesion and thus may be helpful in classification of the cases according to severity. Neoplastic transformation is identified by overexpression of P15 and P16 in premalignant and malignant cases, which plays an important role in cervical carcinogenesis. The immune-histochemical detection of P15 and P16 expression could be a useful indicator of progression in cervical dysplasia."