FLT1 and small cell lung carcinoma: By Fisher's exact test, we found a significant association between TMB‐H and multiple gene mutations, including FAT1, TP53, SPTA1, KEAP1, KMT2D, MAGI2, NOTCH2, NOTCH3, FLT1, KDM6A, and FAT4, in the Chinese SCLC patients (Table S3).