Having established a rapid ex vivo PDX explant preclinical testing platform for the CU-PC01 model, the short-term efficacy of the poly (ADP-ribose) polymerase (PARP) inhibitor olaparib was explored to ascertain if PARP inhibition is efficacious against CU-PC01 PDX tumours carrying a BRCA2 mutation with unknown pathogenicity. This evidence concerns the gene BRCA2 and neoplasm.