CCL2 and cystinosis: We measured serum MCP-1 and cystatin C levels, and found that cystinosis patients have significantly higher levels of the inflammatory cytokine MCP-1 (mean[SD] patients 283.6 [143.3], controls 206.6 [96.2] pg/ml, P = 0.021) as well as renal function marker cystatin C compared to controls (patients 4.39 [1.6], controls 2.29 [0.6], P<0.001) (S2B Fig in S1 File) as previously described [22, 23].