THBS1 and neoplasm: More importantly, overexpression of RRM2 in gastric cancer cells promotes their invasiveness by regulating the AKT/NF-κB signaling pathway (47), and RRM2 increases tumor angiogenesis and growth by modulating the expression of thrombospondin-1 (TSP-1) and vascular endothelial growth factor (VEGF) (48).