Niraparib potentiates the effects of SN-38 in MSI and MSS cell lines. Assessment of synergy with niraparib and SN-38 by excess volume HSA. Each symbol indicates a single experiment with the indicated cell lines. Data was generated from 7 day proliferation assay and excess volume HSA was calculated using a MATLAB algorithm. HSA values from 0.2-0.3 indicate strong synergy, 0.1-0.2 indicated mild synergy, 0.0-0.1 indicate additivity, and negative numbers indicate mild antagonism. Data points are from 1–3 experiments and are only shown if the p value associated with the excess volume HSA is equal to or less than 0.05.