CLU and breast cancer: Our previous study identified PRKD3 as a candidate breast cancer driver gene.[21] When we investigated the PRKD3 interactome using co‐immunoprecipitation (Co‐IP) followed by mass spectrum (MS) identification, we found CLU specifically in the anti‐PRKD3 antibody pull‐down sample, but not in the control IgG sample (Figure 1A and Table S1, Supporting Information).