GRB2 and thyroid gland carcinoma: Noteworthy, the insulin receptor (IR) signaling has been demonstrated to be transactivated by the NGF receptor TrkA via the IR or the IRS1 in neurons and in the pheochromocytoma cell line PC12 [89,90], and by oncogenic fusion protein Trk-T1 from thyroid carcinoma triggering the IRS-Growth factor receptor-bound protein 2 (IRS-Grb2) complex [91].