EBF1 and Decreased total B cell count: Mice lacking NFAT2 in pro-B cells have deficient expression of an essential TF determining B-cell lineage fate, EBF1, and a similar phenotype of EBF1-deficient mice (29) with defective Immunoglobulin (Ig) gene rearrangement, and pre-BCR formation which impairs B cell development and leads to severe B-cell lymphopenia (30).