CD28 and lung carcinoma: The absolute numbers of the CD28+CD57- (Fig. 3a & e), CD28+CD57+ (Fig. 3b & f), and CD28-CD57- cells (Fig. 3c & g) were similar in the cancer patients and controls, even after stratifying the cancer patients based on disease stages, except at the 6th month, where the CD28+CD57- cell counts were lower among the lung cancer patients than the controls, and the 3rd month, in which the absolute number of CD28+CD57+ cells was higher among stage III cancer patients than the controls.