MTAP and ovarian cancer: Additionally, 3 to 6 h after ultraviolet irradiation, the activity of caspase 3/7 was notably high, suggesting that phototherapy was able to induce apoptosis, which indicates that the photoactivation of ZnO-MTAP conjugates may be useful for induction of toxicity in ovarian cancer on exposure to UV-A light, leading to targeted destruction of tumor cells.