PARG loss was the most frequent alteration in PARPi-resistant KB2P tumors and occurred significantly more often in KB2P tumors than in the other tumor groups, even though a few resistant KB1P(M) tumors carried copy-number loss and/or downregulation of Parg. The strong selection for PARG loss in KB2P tumors could result from the impossibility of HR restoration in these tumors. This evidence concerns the gene PARG and neoplasm.