PIK3CA and small cell lung carcinoma: Targeted-capture sequencing of 523 cancer-related genes revealed lower prevalence of mutations in TP53 and RB1 as compared with that in SCLC, as well as detected FGFR3-TACC3 gene fusion and deleterious/likely deleterious gene variants in NOTCH1 and several genes encoding components of the PI3K/AKT/mTOR pathway.