The specific objectives include the following: (i) to elucidate the biological significances of the PARPi targets, PARP1/2, in CRC; (ii) to clarify the roles of HRD in predicting PARPi response in CRC; and (iii) to interrogate the potential predictive relevance of PARP1/2 expression, TP53 mutations, ATM expression, MSI status, aneuploidy and fraction genome altered (FGA) in PARP inhibition, and compare these findings to the HRD scores and HRD surrogates. This evidence concerns the gene TP53 and colorectal carcinoma.