Moreover, calcitriol has antineoplastic activity in cervical cancer by reducing the proliferation of cell lines and the gene expression of well-known oncogenic proteins such as the potassium channel EAG1, and HCCR1 [52,60], as well as the induction of the critical cell cycle regulator p21 (Figure 2) [60]. The gene discussed is LETMD1; the disease is cervical cancer.