IL6 and infection: After infection with L. major, the deficiency of IL-6 in non-hematopoietic cells and keratinocytes (wt→IL-6−/− chimeric mice) resulted in a marked deterioration of disease (Figure 6A), shown by increased footpad swelling as well as by significantly increased numbers of living parasites in footpads (Figure 6B) and lymph-nodes (data not shown) compared to the control groups of mice.