NRP1 and colorectal carcinoma: Additionally, by suppressing Th1 cell activity, Tregs indirectly or directly promote CRC angiogenesis through the inhibition of Th1-derived angiogenesis inhibitors, such as transforming growth factor-beta (TGF-β), and the production of angiogenic factors like neuropilin-1 (NRP-1) (62, 63).