ALK and neoplasm: In our cohort, based on the total RNA extracted from the whole tissue section (it was easier to operate for nonmicrodissection in the clinical laboratory) and proportion of tumor cells on the slides estimated by area, there was no correlation between the percentage of ALK‐positive cells detected by FISH and ALK RNA expression level detected by FIATA‐based RT‐ddPCR, which differed from the findings in previous relevant studies (ie, the positive correlation between the number of ALK fusion cells by FISH and RNA or protein expression by qPCR or IHC28, 31).