Adapter protein that bridges CNOT7, a catalytic subunit of the CCR4-NOT complex, to EIF4E, and facilitates maternal mRNAs decay during the maturation of oocytes and in the fertilized egg (PubMed:27065194). It is therefore required for the maternal-zygotic transition (MZT), zygotic cleavage and initiation of embryonic development (PubMed:27065194). Interacts with CNOT7 and EIF4E (PubMed:27065194). Interacts with CNOT8 (PubMed:27065194). Expressed in oocytes (PubMed:27065194). Expressed in testis and in olfactory epithelium. BTG4-null mice are viable, have body sizes similar to those of their wild type littermates, are healthy up to 1 year of age, and do not spontaneously develop tumors. Females are sterile and their embryos are arrested at the one- or two-cells stage. Belongs to the BTG family.