CD4 and myeloid sarcoma: miR-29b is highly expressed in T lymphocytes (CD4+); This same miRNA (miR-29b) is down-expressed in activated T lymphocytes, which contributes to the pathogenesis of MS since it regulates the T helper response (Th1) of T lymphocytes causing chronic inflammation (Smith et al., 2012; Gao et al., 2021).