PDCD1 and neoplasm: Altogether, the combination treatment with ZSTK474 and anti-PD-1 mAb increases memory T cell formation not only against NY-ESO-1 but also an internal tumor antigen(s) present in parental CMS5a cells and augments durable antitumor effects by a mechanism unrelated to Treg reduction and subsequent activation of T cell response via controlling PI3K signaling in CD8+ T cells.