S100A9 and acute lymphoblastic leukemia: For the blast populations specifically, there exist clusters with cells from T/My MPAL and ETP/near-ETP (cluster 0) and T/My MPAL and non-ETP T-ALL (cluster 7), as well as a distinct myeloid cluster 3 (high expression of S100A9, LYZ, CD14) which contains mostly T/My MPAL blasts (Fig. 3B).