The adhesion between ascites tumor cells and CAFs was mediated by integrin α5, and CAF-released EGF promoted and maintained integrin α5 expression on tumor cells, further potentiating spheroid formation. Importantly, spheroids composed of SK-OV-3 cells and CAFs (heterospheroids) displayed the strongest adhesive capacity and lowest apoptosis rate compared to SK-OV-3-only spheroids and single cells. This evidence concerns the gene EGF and neoplasm.