Munari E, et al. - Using a larger cohort, researchers further analyzed and sought validation for the analytical performance of E1L3N clone (one of the most widely used and inexpensive PD-L1 clone) on Ventana platform. Comparability with assays SP263 and 22C3 run onto their dedicated platforms, was also assessed. On comparing E1L3N with SP263 both at 1% and 50% cutoffs, a very high concordance was reported. At both cutoff, E1L3N vs 22C3 yielded lower overall concordance. Because E1L3N vs both SP263 and 22C3 at 50% cutoff yielded 100% sensitivity and therefore the lack of false negative cases, an algorithm was proposed for PD-L1 testing in NSCLC when considering pembrolizumab as first line therapy.