The serum response factor pathway in myelopoiesis and myelodysplasia with 5q abnormality. DIAPH1, CTNNA1, EGR1, miR143, and miR145 are localized on chromosome 5q and are either upstream or downstream of SRF. RhoA signaling and mDIA can be stimulated with lenalidomide or IMMs, respectively. Loss of mDIA leads to aberrant CD14/TLR4 signaling, whereas loss of SRF leads to aberrant CD11b regulation and loss of migration. CTNNA1, α-catenin; DIAPH1, Diaphanous 1; EGR1, early growth response gene 1; IMM, intramimic; mDIA, mammalian Diaphanous; MRTF, myocardin-related transcription factor; SRF, serum response factor; TLR, toll-like receptor.