The role that cigarette smoke plays in the pathogenesis of tuberculosis is related to ciliary dysfunction, to a reduced immune response, and defects in the immune response of macrophages, with or without a decrease in the CD4 count, increasing susceptibility to infection with Mycobacterium tuberculosis [32], though we did not find any link between cigarette smoking and drug resistance, we think an increase primary and secondary TB transmission, TB relapse, and poor treatment compliance would eventually result in drug resistance. The gene discussed is CD4; the disease is infection.