Combined with the tumors with amino-terminal truncation of FGFR1, the carcinomas with tail-to-tail rearrangements within FGFR1 or in close proximity to the FGFR1 gene locus may thus constitute the overall population of FGFR1-dependent SQLC with sensitivity to FGFR inhibition. Here, FGFR1 is linked to carcinoma.