RUNX1 and myelodysplastic syndrome: There is an overlap of classical IBMFSs and secondary MDS due to MDS-predisposing germline mutations (e.g., RUNX1, ETV6, and GATA2-related disorders), as patients with these mutations can present with MDS without any additional features of IBMFSs.12 The risk of development of cancers differs greatly between the various IBMFSs, and identification of the underlying etiology of marrow failure is imperative to assess the need and type of cancer screening.2