Analysis with localization revealed that frequent co-mutations of APC, KRAS, and TP53 are characteristic of colorectal cancer (CRC), where a triple mutation occurs in 42% of patients, whereas in other nosologies (lung adenocarcinoma, cholangiocarcinoma, glioblastoma), the frequency and co-occurrence of these mutations are significantly lower and statistically insignificant. The gene discussed is KRAS; the disease is cholangiocarcinoma.