TRPC6 is an ion channel that binds to the podocyte-specific membrane protein podocin,7 and activating mutations in this channel in patients are able to cause focal segmental glomerular sclerosis (FSGS).8 Both gain-of-function and loss-of-function mutations are known to cause FSGS.9 In addition, it has been shown in podocytes that thrombin treatment can increase intracellular calcium concentrations. The gene discussed is NPHS2; the disease is focal segmental glomerulosclerosis.