# Common Molecular Mechanisms and Biomarkers in Breast, Colon and Ovarian Cancer
## 3 Results
### Gene Ontology and KEGG Pathways Analysis  
The GO enrichment study showed that the 27 proteins shared between breast, colon, and ovarian cancer participate in 731 biological processes out of a total of 1027 (\(p<\) 0.05, hypergeometric test) (Supplementary Table S5). In Figure 4a, the 20 biological processes with the highest statistical significance (\(p<\) 9 \(\times\) 10\({}^{-5}\)), largest number of implicated genes, and enrichment are shown. The processes with the highest statistical significance included response to gamma radiation (\(p\) = 8.66 \(\times\) 10\({}^{-10}\)), DNA damage response (\(p\) = 8.66 \(\times\) 10\({}^{-10}\)), cell population proliferation (\(p\) = 2.14 \(\times\) 10\({}^{-8}\)), and apoptotic signaling in response to DNA damage (\(p\) = 2.27 \(\times\) 10\({}^{-8}\)). The most enriched processes were the somatic recombination of immunoglobulin gene segments and DNA damage response mediated by p53 signal transduction. The processes with the highest number of implicated genes were apoptosis and its regulation, as well as the response to DNA damage (Supplementary Table S5). The enrichment analysis of cellular components showed the involvement of these proteins in 80 components out of a total of 159 (\(p<\) 0.05, hypergeometric test) (Supplementary Table S6). The most enriched cellular component, which also had the highest probability, was the MutSalpha complex (\(p\) = 1.19 \(\times\) 10\({}^{-4}\)). However, other less enriched cellular components showed high probability, with more implicated proteins. Notably, these include the telomeric region of chromosomes (\(p\) = 1.53 \(\times\) 10\({}^{-4}\)), the protein-containing complex (\(p\) = 9.96 \(\times\) 10\({}^{-5}\)), and the nucleoplasm (\(p\) = 1.19 \(\times\) 10\({}^{-4}\)) (Supplementary Table S6). Figure 4b shows the 20 most significant components based on their statistical probability (\(p<\) 0.01). The study of molecular functions revealed that the 27 common proteins participate in 120 functions out of a total of 208 (\(p<\) 0.05, hypergeometric test) (Supplementary Table S7). Figure 4c presents the 20 most significant functions (\(p<\) 0.005). In this regard, guanine/thymine mispair binding stands out as the most probable (\(p\) = 2.37 \(\times\) 10\({}^{-6}\)) and enriched function. Other functions highlighted due to their high probability and greater number of implicated proteins were enzyme binding (\(p\) = 3.05 \(\times\) 10\({}^{-6}\)), protein homodimerization activity (\(p\) = 3.05 \(\times\) 10\({}^{-6}\)), and identical protein binding (\(p\) = 3.05 \(\times\) 10\({}^{-6}\)) (Supplementary Table S7) (Figure 4c). The KEGG pathway analysis showed the involvement of these 27 proteins in 107 statistically significant pathways out of a total of 172 (\(p<\) 0.05, hypergeometric test) (Supplementary Table S8). The 30 most significant pathways (\(p<\) 3.5 \(\times\) 10\({}^{-7}\)) with the highest number of implicated proteins are shown in Figure 4d. The KEGG pathways that stand out due to their high probability and number of implicated proteins are related to various types of cancer (\(p\)-value ranging from 2.6 \(\times\) 10\({}^{-7}\) to 7.42 \(\times\) 10\({}^{-17}\))--pathways in cancer, endometrial cancer, colorectal cancer, gastric cancer, platinum drug resistance, breast cancer, carbon metabolism in cancer, etc. It is important to highlight the relationship between these common proteins in breast, colon, and ovarian cancer and pathways involved in infections caused by various viruses (\(p\)-value ranging from 2.6 \(\times\) 10\({}^{-7}\) to 2.74 \(\times\) 10\({}^{-9}\))--human T-cell