In this context, our results have shown that inhibition of PIK3CA by siRNA in CRC cell lines has a major impact in cellular viability, not only in cells with mutations in KRAS/PIK3CA but also in those with KRAS mutations i.e. our data indicates that CRC cells with KRAS mutations are sensitive to PI3K p110α inhibition, regardless of PIK3CA concomitant mutations. This evidence concerns the gene KRAS and colorectal carcinoma.