| However , the mechanism ( s ) of SOCS 1 induction by insulin like growth factor ( IGF ) 1 and a role of SOCS 1 on IGF 1 receptor mediated signaling are not clarified . ^^^ Collectively , these findings suggest that SOCS 1 suppresses muscle differentiation through negative feedback regulation of IGF 1 receptor mediated signaling . . ^^^ Suppressor of cytokine signaling 1 suppresses muscle differentiation through modulation of IGF 1 receptor signal transduction . ^^^ |