We evaluated different NK cellular subsets and we identified greater percentages of inhibitory NK cells (CD3− CD56bright CD16− NKG2A+ CD94+ NK cells: Low CD56 group: median = 8.54%, range: 0–90.2%; High CD56 group: median = 31%, range: 0.93–92.9%, Mann–Whitney p = 0.0211, * and CD3− CD56dim CD16+ NKG2A+ CD94+ NK cells: Low CD56 group: median = 3.9%, range: 0–50.9%, High CD56 group: median = 14.4%, range: 0–95%, Mann–Whitney p = 0.0040, **) in patients with more than 10% of CD56-expressing clonal MM cells (Fig. 5B, C). Here, KLRD1 is linked to Miyoshi myopathy.