BRD2 and breast cancer: Between December 2017 and March 2021, a total of 116 BC patients appropriate for NAT in Sun Yat‐Sen University cancer center were enrolled, pre‐NAC baseline blood samples were taken for further flow cytometry analysis to quantitatively evaluate the PBLs subsets distribution, and corresponding clinical information including pathological complete response (pCR) rate of NAT response were recorded.