Due to the involvement of RBBP4/7 in several multi-protein transcription complexes other than ISWI, there has been no exact conclusion as to whether RBBP4 and RBBP7 execute these functions in an ISWI or non-ISWI-dependent manner in breast cancer (Abbey et al., 2018; Moody et al., 2018; Glancy et al., 2021). This evidence concerns the gene SMARCA5 and breast cancer.