In a study on tumors, histone deacetylase 2 (HDAC2) and HDAC3 were found to downregulate KCa3.1 transcript levels in a REST-independent and insulin-like growth factor-binding protein 5 (IGFBP5)-independent manner in the breast cancer cell line, TMB-1 (27). Here, IGFBP5 is linked to breast carcinoma.