PIK3CA and colorectal carcinoma: In the group of CRC patients aged 50 years or younger, the most common mutations were APC (80 %), TP53 (61 %), TTN (48 %), KRAS (43 %), SYNE1 (28 %), PIK3CA (25 %), MUC16 (24 %), FAT4 (23 %), RYR2 (19 %), ZFHX4 (19 %), and OBSCN (19 %) (Fig. 3B).