CD274 and adenocarcinoma: The SP142 PD‐L1 IHC assay (Ventana) detected that the prevalence of PD‐L1 expression ranged from 50% to 55% in squamous NSCLC,15, 25, 37, 38, 39 but was almost less than 40% in adenocarcinoma NSCLC.16, 25, 39