CD123
CD123 is the alpha subunit of the interleukin-3 receptor, a heterodimeric cytokine receptor that pairs with the common beta chain CD131 to relay IL-3 signaling through the JAK-STAT and MAPK pathways. It is expressed on myeloid progenitors, monocytes, basophils, and dendritic cells, where it supports proliferation and survival. Importantly, CD123 is strongly overexpressed on leukemic stem cells in acute myeloid leukemia and on plasmacytoid dendritic cells in blastic plasmacytoid dendritic cell neoplasm, making it a prominent target for antibody-drug conjugates and CAR-T strategies in these diseases. Association with CD131 is required for high-affinity IL-3 binding and efficient intracellular signaling.
