Additionally, a retrospective study disclosed that the PD-1/PD-L1 antibody may be an independent risk factor for zoster [10], although immunosuppressive drugs used against irAEs were also linked with zoster [11]. It is difficult to distinguish zosters from non-HIV IRIS because the timing of non-HIV IRIS varies widely from case to case [8,10]. This evidence concerns the gene PDCD1 and herpes zoster.