The expression of NT5C2 plays an important role in lung cancer,[10] acute leukemia,[35] and astrocytoma.[36] In breast cancer, by regulating ROS metabolism and defense, NT5C2 regulates cellular responses to glucose deprivation.[19] The expression of NT5DC2 was correlated with glioblastoma,[13] hepatocellular carcinoma,[15] colorectal carcinoma,[17] lung cancer,[37] and leiomyosarcoma.[38] There are no studies about NT5DC1, NT5DC3, and NT5DC4 in cancer. This evidence concerns the gene NT5DC4 and breast cancer.