In a large in vivo study, GZP accumulation in the tumor had an overall positive predictive value of 84% for anti-PD-1 and anti-CTLA-4 immunotherapy response in the murine colon cell lines CT26 and MC38-tumor- bearing mice (N=31) and a negative predictive value of 94% (N=35) [98]. Here, PDCD1 is linked to neoplasm.