RETNLB and infection: A slight decrease in the levels of Arg-1 and Fizz-1 mRNA was detected in Cre+ compared to Cre- cells; moreover, IL-10 mRNA was not upregulated in HIF-1α deficient BMM following infection with L. donovani. To be sure that HIF-1α was indeed deleted in BMM from conditional knockouts, we assessed the expression of HIF-1α and two HIF-1α downstream targets, Pgk-1 and Glut-1 in cytokine-treated and infected BMM.