Other studies have investigated RANKL and glycoprotein osteoprotegerin expression in lymphoblastic leukaemia along with vitamin D and K supplement use in children [37]; juvenile idiopathic arthritis [38]; postmenopausal osteoporosis in older women [39]; and secondary hyperparathyroidism [40]. The gene discussed is TNFRSF11B; the disease is secondary hyperparathyroidism.