BRCA1 and neoplasm: In the human PPI network, the connection between the bottleneck proteins PP1CC and BRCA1, agrees with a previous report showing that the tumor suppressor BRCA1 protein interacts with the polyadenylation protein CstF50 to promote deadenylation activity of the poly(A)-specific ribonuclease PARN during DNA damage, leading to RNA degradation [78].