Although relapse-free F-MS showed no significant difference in the frequency of CD56+ cells in CCR7− T cells compared to in HS and nF-MS, the four relapsed F-MS patients showed a significantly higher frequency of CD56+ cells within the CCR7− T cell population compared to all other groups (p < 0.003) (Fig. 2d, left). Here, NCAM1 is linked to myeloid sarcoma.