It was also shown to increase the expression of COX-2 encoding cyclooxygenase-2 to inhibit ultraviolet B (290–320 nm)-induced skin cancer growth and epidermal thickening, however, the experiment used a mouse skin cancer model induced by ultraviolet radiation, which is different from the pathological process of spontaneous human skin cancer (Lee et al., 2017). Here, PTGS2 is linked to skin cancer.