Our data showed that the AP5 signal was strongly induced and expressed along the cell membrane when podocytes were incubated with urine of patients with primary FSGS and recombinant suPAR, but the AP5 signal was very weak when podocytes were incubated with normal urine, bovine serum albumin or RPMI 1640. Here, ALB is linked to focal segmental glomerulosclerosis.