Mast cell differentiation: Still open questions?

Abstract

In this issue of Blood, Dahlin et al report on a minor circulating human mast cell (MC) progenitor cell population (lineage-negative [Lin-]/CD34hi/CD117int/hi/ high-affinity immunoglobulin E receptor-positive [FceRI1]), with an immature MC-like appearance, which is present in the peripheral blood (PB) of healthy individuals and of asthma subjects well controlled by treatment or with reduced lung function1.