CD4 and neoplasm: To determine the effect of pDNA GET on CT26 tumors via SHV or HV-LV pulse protocols on the recruitment of immune cell subpopulations, immunofluorescence analysis of CD4+ helper and CD8+ cytotoxic T cells, as well as F4/80+ macrophages, was performed on tumor tissues collected 3 and 7 days after therapy (Figure 2).