Figure 2.

Schematic diagram of tumor environment in renal cell carcinoma with currently available therapeutic drug targets. Created with Biorender.com. (a) Intratumoral cell hypoxia leads to PI3K pathway pVHL activation, leading to HIF accumulation and altered cellular transcription, with downstream effects including angiogenesis factor production. (b) Various receptors and pro-angiogenic factors that interact with endothelial cells. (c) Immune checkpoints on regulatory T cells such as PD-1 and CTLA-4 are integral to the anti-tumor response, and their inhibition allows T cells to activate and cause cell death.