basophil progenitor cell basophilic stem cell BaP A progenitor cell committed to the basophil lineage. This cell lacks hematopoietic lineage markers (lin-negative) and is CD34-positive, T1/ST2-low, CD117-negative, and FceRIa-high. This cell also expresses Gata-1, Gata-2 and C/EBPa. BaP are also CD13-low and integrin beta-7-low. They are lin-negative (CD2, CD3e, CD4, CD5, CD8, CD11b, CD14, CD19, CD20, ly6g, ly76, and NCAM-1). They also lack expression of mast cell protease 1 (MCP-1) and microphthalmia-associated transcription factor (mitf). CFU-Bas colony forming unit basophil myeloid cell granulocytopoietic cell