(A) Flow chart of cross-species phenotypic drug discovery process showing results of the primary drug screen, secondary confirmation, orthogonal assays, mouse model tests, shared MOA and complementary MOA assays (i.e. paired drug tests). (B) Summary of survival effects of lead drug candidates across model systems. (C) Summary of survival effects of paired lead drug tests in the zebrafish-inducible RP model showing effects of single drug controls (blue boxes) and paired drug tests that resulted in no additive effects (gray boxes), additive effects (orange boxes) and synergistic effects (red boxes); mathematically summed effect of each pair of lead compounds (italics) are shown for comparison. Abbreviations: as in prior figures.