Unexpectedly, we found that Niraparib inhibited STAT3 phosphorylation, shown as a reduction in pSTAT3(Y-705) following treatment with Niraparib in both MIA PaCa-2 and PANC-1 human PDAC cell lines and OVCAR8 and PEO1 ovarian cancer cells (Figure 2A), despite reduced PARylation by Niraparib (Figure S2A). Here, STAT3 is linked to ovarian carcinoma.