PIK3CA and rectal cancer: A similar pattern was detectable in rectal cancer, where PIK3CA and PTEN alterations were significantly overrepresented in the RAS/BRAF‐altered subgroup and EGFR, ERBB2, FGFR1, and FGFR3 alterations were significantly overrepresented in the RAS/BRAF‐wt subgroup (Fig. 4B).