NPHS1 and focal segmental glomerulosclerosis: In case of primary or mutation-induced FSGS, mutations in genes encoding proteins expressed in podocytes, which are mostly related to slit diaphragm structure, the actin cytoskeleton, or foot processes, such as nephrin (NPHS1), podocin (NPHS2), actinin α4 (ACTN4), and TRPC6 are commonly observed (Lim et al., 2016).