EGFR and prostate cancer: In addition, it was shown that ADAM17 (also known as tumor necrosis factor-α converting enzyme; TACE), an enzyme involved in proteolytic ectodomain shedding of cell surface molecules and cytokines, contributed to androgen-independent prostate cancer cell invasion by shedding of EGFR ligand TGF-α, which subsequently activated the EGFR-MEK-ERK signaling pathway, finally leading to overexpression of MMP-2 and -9 [74].