TLR4 expression on developing megakaryocytes by flow cytometry. Cultured and harvested megakaryocytes from fetal liver were double stained for CD41 and TLR4 expression. (A) TLR4 expression for isotype control and the different levels (low, medium, high) of CD41 expression. (B) Mean fluorescence intensity obtained for the low, medium, and high levels of CD41 expression.