PARP1 and cancer: In summary, although ADP-ribosylation has already proven its high medical relevance in cancer through the success of canonical PARPi, the field is currently exploring new possibilities, such as developing more specific PARP1 inhibitors, therapies to address PARPi resistance, combination treatments, inhibitors that target other PARPs, and investigating the potential applications of PARPi for non-cancer-related conditions.