Moreover, both the etiology and histology of FSGS as well as of MCD may be very variable, including: viral infections, toxic agents, adaptive structural-functional responses, and mutations in the genes encoding proteins specific for podocytes (or highly expressed in them) [1–3], such as: ACTN4 [4], INF2 [5], and TRPC6 [6]. This evidence concerns the gene ACTN4 and focal segmental glomerulosclerosis.