IL2 and neoplasm: In addition, expression of key cytokine genes was lower in KDR-V compared with KDR-WT tumors, such as interleukin-2, which is known for its well-characterized role as a T-cell growth factor leading to the growth and expansion of T-cells, particularly CD8+ T-cells, and documented anti-tumor efficacy in advanced renal cancer and melanoma [33].