T1 B cell
t1 b cell
"A transitional stage B cell that migrates from the bone marrow into the peripheral circulation, and finally to the spleen. This cell type has the phenotype surface IgM-positive, surface IgD-negative, CD21-negative, CD23-negative, and CD62L-negative, and CD93-positive. This cell type has also been described as IgM-high, CD19-positive, B220-positive, AA4-positive, and CD23-negative."