## 3 Discussion  
The present study examined the impact of the rs1051931 SNP of the _PLA2G7_ gene on postoperative pain-related phenotypes in patients who underwent SSRO and laparoscopic gynecological surgery. In patients who underwent SSRO, the presence or absence of dysesthesia was evaluated. In patients who underwent laparoscopic gynecological surgery, postoperative pain within 24 h was assessed. Carriers of the CC genotype of _PLA2G7_ rs1051931 were more prone to the development and exacerbation of dysesthesia and postoperative pain than those with TT + TC genotypes. These results suggest that the CC genotype of _PLA2G7_ rs1051931 is associated with postoperative pain, including neuropathic pain. In animal models, PAF was shown to induce new PAF production in a feedback loop to exacerbate neuropathic pain [15]. The administration of a small amount of PAF into the spinal cord in mice caused allodynia, which is related to neuropathic pain, and hyperalgesia [17]. Furthermore, the intrathecal spinal administration of a PAFR antagonist alleviated neuropathic pain [17]. PAF also exacerbates nociceptive and inflammatory postoperative pain [26]. These findings align with the present results in humans, in which CC carriers of _PLA2G7_ rs1051931, which is related to a decrease in PAF-AH activity in plasma, were associated with postoperative pain, including neuropathic pain. Thus, the increase in PAF through a decrease in PAF-AH activity may contribute to the development and exacerbation of a prodromal symptom of neuropathic pain, dysesthesia, and postoperative pain in humans. PAF-AH degrades PAF, which is involved in neuropathic pain [15]. The base substitution from T to C in the rs1051931 polymorphism of the _PLA2G7_ gene causes an amino  
Figure 1: Associations between genotypes of _PLA2G7_ rs1051931 and NRS pain scores in the JUH group. The data are expressed as box and whisker plots. The upper and lower ends of the boxes represent the 75 th and 25 th percentiles, respectively. Whiskers represent the highest and lowest values. Medians are depicted by solid horizontal lines in the boxes. Mean values are depicted by crosses. Each NRS value is depicted by a red dot. The samples were divided into two groups in the dominant model (TT + TC and CC). TT + TC, \(n=64\); CC, \(n=268\); \({}^{*}p<0.05\). acid substitution from Val to Ala of PLA2G7, plasma type PAF-AH [35]. CC carriers of the _PLA2G7_ rs1051931 polymorphism have reportedly exhibited a decrease in PAF-AH activity in an aliquot of plasma [34; 36; 37; 38], with the exception of one study [39]. [PERSON] et al. reported that mean PAF-AH activity in an aliquot of plasma was TT (Val/Val) \(>\) TC (Val/Ala) \(>\) CC (Ala/Ala) [37], and [PERSON] et al. reported TT \(>\) TC + CC [38]. However, we cannot discern the reason for the lower PAF-AH activity in an aliquot of plasma (i.e., whether it is attributable to a decrease in PAF-AH activity of _PLA2G7_ or a decrease in _PLA2G7_ mass) that depended on genotypes of _PLA2G7_ rs1051931. [PERSON] et al. indicated that the mean mass of PAF-AH in plasma was TT \(>\) TC \(>\) CC [37]. Similarly, the result of expression quantitative trait locus (eQTL) by a public GTEx portal database indicates that _PLA2G7_ mRNA expression in AA, AG, and GG genotypes of _PLA2G7_ rs1051931 (TT, TC, and CC genotypes according to the orientation of the _PLA2G7_ gene) is of a reduced order in a linear regression model (normalized effect size (NES) = \(-0.25\), \(p=5.56\times 10^{7}\), Supplementary Figure S1) [40]. These findings indicate that the mass of plasma-type PAF-AH/PLA2G7 is TT \(>\) TC \(>\) CC, resulting in the amount of PAF in plasma being TT \(<\) TC \(<\) CC.