PDCD1 and cancer: In addition, although other studies have reported that the acquisition of EMT-like properties induces the expression of PD-L1 by cancer cells87–91, in this scenario, it is challenging to explain why the induction of the EMT program is associated with anti-PD-1 resistance92, as immune evasion might be expected to be based on the PD-1/PD-L1 axis in these mesenchymal tumors.