In this study, in vitro and in vivo data suggested that CRM197 treatment sensitized paclitaxel‐resistant ovarian cancer cells to paclitaxel, at least in part, via nucleus accumbens‐1 (NAC‐1) and its downstream pathway, DNA damage‐inducible 45‐γ interacting protein (Gadd45gip1)/growth arrest and DNA damage‐inducible 45 (Gadd45), in A2780/Taxol and SKOV3/Taxol cells. Here, GADD45A is linked to ovarian carcinoma.