PDCD1 and cyclic hematopoiesis: Taken together, the results implied that anti-PD-1 tended be more effective than anti-PD-L1 in activation of WHV-specific CTLs in PBMC from animals with CH, i.e., 3/8 animals with ≥ 50% and 1/8 with < 50% cells activated giving in total 4/8 after anti-PD-1 treatment (range from 0 to 141.2% ± SEM 23.4) versus 1/8 with ≥ 50% and 1/8 with < 50% cells activated resulting in the total of 2/8 animals after treatment with anti-PD-L1 (range from 0 to 114.3% ± SEM 4.5); however statistically significant difference was not achieved (p = 0.41).