SMAD4 and colorectal carcinoma: TP53 and APC gene mutation in also similarly high in other countries such as Japan and US, although there are significant differences in mutation types between the two countries.32 In China, KRAS, APC, and TP53 genes are also commonly mutated in CRC cases, along with CHEK2, MDC1, GNAQ, and SMAD4.33 Similarly, these genes are also known to be frequently mutated among patients of African and European descent.