In fact, it has been demonstrated that 53% of cases of papillary thyroid carcinoma are estrogen-receptor (ER) positive; the estrogen-receptor pathway, which also includes extracellular signal-regulated kinases (ERK) and p38 mitogen-activated protein kinases, is a class of mitogen-activated protein kinases (p38 MAPK) that induce proliferation and migration of cancer cells via the action of miR-219-5p and promote metastasis spread [30] (Figure 2). Here, ESR1 is linked to cancer.