NCAM1 and myelodysplastic syndrome: Considering the simultaneous decreased fractions of CD14+lowCD16+ and increased fractions of CD14+highCD56+ monocytes observed in MDS patients, we postulate that blockage of differentiation of classical (CD14+highCD16−) into proinflammatory (CD14+lowCD16+) monocytes leads to accumulation of the first monocyte population in the PB, which becomes senescent and then acquire CD56 expression.