TNFRSF11A and congenital secretory chloride diarrhea 1: RANK, RANKL and OPG are the members of TNF superfamily and osteoprotegerin competes with RANKL for binding with RANK that result in its activation that are necessary to start several biochemical cascades.5 Osteoprotegerin to osteoclastogenesis inhibitory factor proportion is higher in those having CLD.