Gene Ontology analysis revealed that only the genes downregulated in CD4+ T cells growing without cancer cells were defined in several processes such as apoptosis, regulation of autophagy, transcription, RNA biosynthesis, and stress response, while for T15M no defined processes were found (Figure 2D and Supplementary Materials, Table S2), further supporting the conclusion that co-cultivation of activated CD4+ T cells with cancer cells leads to specific upregulation of important regulatory processes, which may result in the cancer progression and immune system dysfunction. Here, CD4 is linked to cancer.