As most APOL1 nephropathies are either podocyte diseases (focal segmental glomerulosclerosis, HIV-associated nephropathy) or glomerular and vascular diseases (arterionephrosclerosis), it appears that APOL1 risk variant expression in podocytes and possibly renal vascular cells contributes to kidney disease. The gene discussed is APOL1; the disease is focal segmental glomerulosclerosis.