PIK3CA and cholangiocarcinoma: Genomic studies on CCA patients have highlighted some frequent genomic alterations, including mutations of TP53 and SMAD4, ARID1A, ARID2, BAP1, KRAS, PIK3CA, NRAS, and IDH1 genes [20,21,22,23,24], mutations and/or amplification of the EGFR family member genes [21], and the rearrangement of the FGFR2 receptor [25].