They are mutually exclusive subunits of the BAF complex (i.e., the BAF chromatin remodeling complexes can contain either ARID1A or ARID1B, but not both).[11, 13, 16] It has been previously reported that ARID1A‐ or ARID1B‐containing BAF complexes play opposing roles in regulating cell proliferation and osteoblast differentiation.[13, 15, 16, 31, 32] Given this notion, we sought to determine whether OE of ARID1B has any impact on the composition of the BAF complex in breast cancer cells. Here, ARID1B is linked to breast cancer.