In comparison with the sjTRECs in healthy individuals (3.76 ± 3.42 copies/1000 PBMCs, 5.87 ± 4.96 copies/1000 CD3+ cells, 5.62 ± 6.45 copies/1000 CD4+ T cells, 6.79 ± 7.1 copies/1000 CD8+T cells), a dramatic reduction of sjTRECs values was found in patients with CML (0.23 ± 0.38 copies/1000 PBMCs, 1.34 ± 1.63 copies/1000 CD3+ cells, 1.49 ± 1.88/1000 CD4+ T cells, 2.52 ± 2.43 copies/1000 CD8+ T cells) (p < 0.0001, p < 0.0001, p = 0.0115 and p = 0.0129, respectively). The gene discussed is CD8A; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.