Currently, based on TCGA data from 2017 in MIBC five subtypes were identified, namely luminal‐papillary, luminal‐infiltrated, luminal, basal squamous, and neuronal.27 In basal subtypes of breast cancer—triple negative breast cancer,28, 29 the growth and proliferation depend on the BRM and BRG1 central ATPases of the SWI/SNF CRCs, which is involved in the control of numerous regulatory processes.30 In samples of advanced MIBC the strong decrease of BRM protein level corresponding to downregulation of SMARCA2 gene expression was detected. This evidence concerns the gene SMARCA4 and breast cancer.