Acts as a transcriptional repressor. May function in the assembly and/or enzymatic activity of the mSin3A corepressor complex or in mediating interactions between the complex and other regulatory complexes. Component of a mSin3A corepressor complex that contains SIN3A, SAP130, SUDS3/SAP45, ARID4B/SAP180, HDAC1 and HDAC2. Interacts (released by dead or dying cells) with CLEC4E (By similarity). Expressed in various cancer cell ines. The N-terminus may interact with a transcriptional coactivator. The C-terminus may interact with HDAC-dependent and HDAC-independent corepressors. Acetylated. Sumoylated with SUMO1. Belongs to the SAP130 family.