This gene encodes a protein with sequence similarity to retinoblastoma-binding protein-1. The encoded protein is a subunit of the histone deacetylase-dependant SIN3A transcriptional corepressor complex, which functions in diverse cellular processes including proliferation, differentiation, apoptosis, oncogenesis, and cell fate determination. The gene product is recognized by IgG antibody isolated from a breast cancer patient and appears to be a molecular marker associated with a broad range of human malignancies. Alternate transcriptional splice variants encoding different isoforms have been characterized.ARID4B (AT-Rich Interaction Domain 4B) is a Protein Coding gene. Diseases associated with ARID4B include Breast Cancer. Among its related pathways are Development NOTCH1-mediated pathway for NF-KB activity modulation and Activated PKN1 stimulates transcription of AR (androgen receptor) regulated genes KLK2 and KLK3. GO annotations related to this gene include transcription regulatory region DNA binding. An important paralog of this gene is ARID4A.