ALK and adenocarcinoma: In keeping with this, the tumor mutational burden in our ALK+ LCNEC case was 3.91 mut/Mb, which is significantly lower than that of other NSCLC-like LCNEC (average >10 mut/Mb) (Rekhtman et al. 2016), but higher than that of most ALK+ adenocarcinomas (mean < 3.0 mut/Mb, and even lower, <2 mut/Mb, for TP53wt cases) (Christopoulos et al. 2019b).