SMAD4 and small cell lung carcinoma: Overall, low-grade tumors (AC and TC) had fewer mutations than high grade tumors (SCLC and LCNEC), and the following genes were associated with specific tumor types: JAK3, NRAS, RB1, and VHL1 with SCLC; FGFR2 with LCNEC; KIT, PTEN, HNF1A, and SMO with AC; and SMAD4 with TC [54].