In 2013, a follow-up study detected B7-1 expression in podocytes in a number of human proteinuric diseases and excitingly, a B7-1 blocker abatacept was used to successfully treat a small cohort of patients with a resistant form of recurrent focal segmental glomerulosclerosis (FSGS) (17). Here, CD80 is linked to focal segmental glomerulosclerosis.