CD4 and cancer: In parallel, the methylation of the first intron has been shown by functional studies to have both positive and negative correlation with gene expression in specific genes in cancer cell lines, fetal and adult tissues [39], CD4+ cell lines isolated from mice [40], during lineage specification in T cells [41], in multiple myeloma cell lines [42], in leukocytes of patients with schizophrenia [43] and in blood samples isolated from children [44].