The CD4+ T cell count has been shown to be influenced by sex, age, race, time of specimen collection (diurnal rhythms), physical and psychological stress, pregnancy, drug administration (zidovudine, cephalosporin, cancer chemotherapy, nicotine and steroids), tuberculosis, viral infections, presence of anti-lymphocyte auto antibodies and procedures like splenectomy16, 17. Here, CD4 is linked to tuberculosis.