Qa-2 associated lipid rafts are indispensable in the final maturation of CD4+CD8− thymocytes

► Qa-2 expression level correlates with the proliferation capacity of CD4 SP4. ► Qa-2 is localized in lipid rafts of CD4 SP4 cells. ► Lipid raft components up-regulate with the maturation of CD4 SP. ► The integrity of lipid rafts is indispensable for CD4 SP maturation.