CXCL12 and thyroid cancer: We also selected CXCR4 (C-X-C motif chemokine receptor 4), since this gene was shown to be a direct target of miR-126-3p in colon and thyroid cancer cells [42, 46] and the CXCR4/CXCL12 (C-X-C motif chemokine ligand 12) axis is known to promote melanoma cell proliferation and invasiveness [47].