ACTN4, ACTN4 mutants, EGF, FSGS, FSGS mutants, FSGS mutation, Focal segmental glomerulosclerosis, K225E, K255E, N, S262P, T259I, Y265E, actin, actin binding domain, actin binding domains, actin filaments, alpha-actinin-4, cells, epidermal growth factor, fibroblasts, focal segmental glomerulosclerosis, glomerulosclerotic, glutamic acid, humans, isoleucine, lysine, lysine 255 to glutamic acid, melanoma, melanoma cells, patients, podocytes, proline, serine, serine 262 to proline, threonine, threonine 259 to isoleucine, tyrosine, tyrosine kinase, tyrosines, wild type ACTN4