The function of BTG2 (BTG anti-proliferation factor 2, Ensembl gene identifier ENSG00000159388) is as follows. Anti-proliferative protein; the function is mediated by association with deadenylase subunits of the CCR4-NOT complex. Activates mRNA deadenylation in a CNOT6 and CNOT7-dependent manner. In vitro can inhibit deadenylase activity of CNOT7 and CNOT8. Involved in cell cycle regulation. Could be involved in the growth arrest and differentiation of the neuronal precursors (By similarity). Modulates transcription regulation mediated by ESR1. Involved in mitochondrial depolarization and neurite outgrowth. {ECO:0000250, ECO:0000269|PubMed:12771185, ECO:0000269|PubMed:15788397, ECO:0000269|PubMed:18337750, ECO:0000269|PubMed:18773938, ECO:0000269|PubMed:23236473}.