CD19 and malaria: To investigate the phenotype and function of malaria-associated atypical MBCs we performed genome-wide expression profiling of purified B cells magnetically sorted to obtain naïve B cells (CD19+CD21+CD27−), classical MBCs (CD19+CD21+CD27+) and atypical MBCs (CD19+CD21−CD27−) from a subset of 20 uninfected Malian adults (blood smear negative) with lifelong exposure to intense malaria transmission.