[Isoform 1]: Acts as an adapter protein that plays a role in intracellular signaling cascades triggered either by the cell surface activated epidermal growth factor receptor and/or cytoplasmic protein tyrosine kinases. Promotes activation of the MAPK/ERK signaling pathway. Plays a role in the regulation of cell proliferation. . This is the function of GAREM1 (GRB2 associated regulator of MAPK1 subtype 1, Ensembl gene identifier ENSG00000141441).