PDCD1 and cancer: Pegilodecakin treatment induced the hallmarks of CD8+ T-cell immunity in cancer patients, including the systemic elevation of IFNg and GranzymeB levels, expansion and activation of CD8+ TILs, invigoration and expansion of PD-1+/Lag-3+ CD8+ T-cell sub-set and the de-novo expansion of T-cell clones.