Anti-proliferative protein; the function is mediated by association with deadenylase subunits of the CCR4-NOT complex (PubMed:23236473, PubMed:8632892). Mediates CPEB3-accelerated mRNA deadenylation by binding to CPEB3 and recruiting CNOT7 which leads to target mRNA deadenylation and decay (PubMed:21336257). {ECO:0000269|PubMed:21336257, ECO:0000269|PubMed:23236473, ECO:0000269|PubMed:8632892}. This is the function of TOB1 (transducer of ERBB2, 1, ENSG00000141232).