AbstractPericytes and endothelial cells (ECs) constitute the fundamental components of blood vessels. While the role of ECs in tumor angiogenesis and the tumor microenvironment is well appreciated, pericyte function in tumors remains underexplored. In this study, we used pericyte-specific deletion of the nitric oxide (NO) receptor, soluble guanylate cyclase (sGC), to investigate via single-cell RNA sequencing how pericytes influence the vascular niche and the tumor microenvironment. Our findings demonstrate that pericyte sGC deletion disrupts EC–pericyte interactions, impairing Notch-mediated intercellular communication and triggering extensive transcriptomic reprogramming in both pericytes and ECs. These changes further extended their influence to neighboring cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) through paracrine signaling, collectively suppressing tumor growth. Inhibition of pericyte sGC has minimal impact on quiescent vessels but significantly increases the vulnerability of angiogenic tumor vessels to conventional anti-angiogenic therapy. In conclusion, our findings elucidate the role of pericytes in shaping the tumor vascular niche and tumor microenvironment and support pericyte sGC targeting as a promising strategy for improving anti-angiogenic therapy for cancer treatment.