FOXA1 and Burkitt lymphoma: The relative FOXA1 ratio was also positive in all MA cases whatever the IHC staining (Figure 2), but the mean FOXA1 ratio was not significantly different in the IHC(+) and IHC (-) group (mean ratio 660.3 versus 524.3) In the BL subgroup, lack of FOXA1 expression was concordant at the mRNA and protein levels but four FOXA1 IHC(+) tumors could not be detected at the mRNA level.