In CD34+ hHSC-reconstituted, tumor-bearing models, treatment with LY3300054 resulted in an increase of the absolute number of human T cells, an enhanced CD8/CD4 T cell ratio, and increased frequency of PD1+ CD8+ and CD4+ T cells, indicative of T cell activation (Fig. 6a-d). The gene discussed is PDCD1; the disease is neoplasm.