STAT3 and neoplasm: Though often overlooked, PD-L1 has several tumor intrinsic functions that have recently been identified to regulate mTOR/AKT (Chang et al, 2015; Clark et al, 2016), MAPK (Wu et al, 2018), STAT3/Caspase 7 (Gato-Canas et al, 2017), integrin β4 (Wang et al, 2018), MerTK (Du et al, 2021), and BIM/BIK (Feng et al, 2019) signaling, among others.