S100A9 and leukemia: Furthermore, administration of theS100a9/S100a8 inhibitor impedes leukemia development fromPtpn11E76K/+ mutant stem cells (Fig. 8F–8P).These results strongly suggest that the overexpression of S100a9 and S100a8 byPtpn11- mutated stem cells plays a pivotal role in the initialleukemogenic process.