PPM1D and myelodysplastic syndrome: Additionally, due to the cost and limited application of NGS, molecular testing is not routine for all MDS patients, and we noted that genes such as ETNK1, GNB1, NF1, PPM1D, and PRPF8 were not expressed in our patients, which cannot exclude the possibility of data omission due to the nature of a single-center retrospective study.