CD4 and cancer: To mimic studies of the immune response in human cancer [22], the extracted cells were incubated in the presence of PMA and ionomycin for 4 h and were analysed for expression of surface markers to detect CD4+ and CD8+ T cells, as well as Vα2+Vβ5+ to detect antigen-specific T cells, in conjunction with intracellular IFN-γ.