The Li laboratory studies HDL and scavenger receptor BI (SR-BI). SR-BI is a receptor of HDL which plays a pivotal role in modulating HDL metabolism. While high HDL is well-recognized as a cardio-protective factor, mice deficient in SR-BI have a 2-fold increase in HDL levels but are susceptible to atherosclerosis, suggesting dysfunctional HDL in the absence of SR-BI. One of the focuses is to understand the mechanism of HDL dysfunction and its contribution to inflammatory diseases. Using SR-BI null mice, Li laboratory first reveals that SR-BI is a critical protective molecule against sepsis- a devastating disease costs 225,000 lives in US alone. Research focuses on understanding the molecular mechanisms underlying SR-BI protection with molecular, cellular and in vivo approaches, and translating the mechanistic study into effective therapy for sepsis.