After treatment with PARPi, PARPi-resistant cells (SW480) (Fig. 2e, right lower panel; 2f) displayed increased RAD51 foci formation compared to PARPi-sensitive colon cancer cells (Caco-2) which displayed a significantly weaker HR DNA repair response characterized by lower RAD51 foci formation (Fig. 2e, right upper panel; 2f). This evidence concerns the gene RAD51 and malignant colon neoplasm.