DDR1 and retinoblastoma: For instance, angiogenesis is consistently elevated in five stroma-rich solid tumors—retinoblastoma (RB), prostate adenocarcinoma (PRAD), OV, colorectal cancer (CRC), and high-grade glioma (HGG)—suggesting that DDR1 may facilitate neovascularization by aligning tumor collagen fibers to guide endothelial cell invasion.