PIK3CA and colorectal carcinoma: In line with the assumption that NTRK-fusion-driven cancers are largely devoid of other oncogenic drivers, NTRK gene fusions were less likely to co-occur with common drivers, such as those involved in MAPK and PI3K signalling pathways (KRAS, PIK3CA) and with known oncogenic driver genes in breast cancer, CRC and NSCLC.