Expression of CD42 and CD41 by MK developing in culture in the presence of TPO and/or IL-3. (A) Histogram of the expression of CD42 after 7 days in culture. (B) Histogram of the expression of CD41 after 7 days in culture. The staining was performed as described in Materials and Methods. (▪) TPO; () IL-3; ( — ) TPO + IL-3; (- - -) isotype control.