PIK3CA and neoplasm: As a result, β-catenin accumulates in the nucleus, binds the TCF/LEF transcription factors and induces the expression of target genes that play key roles in tumor progression.3 Activation of this pathway contributes to the onset and progression of more than 90% of CRC cases.4 Studies show that 20% of CRC patients present mutations in genes of the PI3K pathway such as, PIK3RI, PI3KCA and PTEN.