Our data indicate that the levels of two blood markers, namely, PAI-1 and MCP-1, were increased among obese children with OSA, such that plasma concentrations of MCP-1 > 30 pg /mL and PAI-1 > 3.3 ng/mL provide reliable prediction on the presence of OSA. The gene discussed is SERPINE1; the disease is obstructive sleep apnea syndrome.