PDCD1 and neoplasm: Research avenues concern new strategies to improve the therapeutic index of this combination including manipulation of the tumor microenvironment, by combining new drugs such as 4-1BB agonist monoclonal antibodies or bispecific antibodies targeting both PD-1 and TGF-β, and reflection on the type of RT to be combined with ICIs, mainly techniques enabling high doses to be delivered per fraction such as SBRT or brachytherapy.