IL4 and tuberculosis: It can promote and maintain the proliferation of Th2 cells, induce a humoral immune response, inhibits the immune response of Th1 cells to nodules, and impede the host’s ability to control bacterial numbers.[8] All these interactions might eventually produce adverse effects on tuberculosis patients.[9] Higher production of IL-4 in patients with tuberculosis was primarily observed in individuals with advanced involvement of lung parenchymal cells and high bacterial loads in the sputum.[10] The IL-4 concentration may help healthcare providers diagnose and manage patients’ conditions.