MEOX1 (mesenchyme homeobox 1) is a mesodermal transcription factor with dual roles in developmental and pathological contexts. Developmentally, MEOX1 is required for somitogenesis and sclerotome development, maintaining sclerotome polarity and enabling cranio-cervical joint formation 1. It regulates hematopoietic stem cell induction through endotome specification within somites 2. In disease contexts, MEOX1 has emerged as a critical regulator of pathological fibroblast activation. During cardiac stress, IL-1β signaling activates a RELA-dependent enhancer near MEOX1, driving fibroblast activation and profibrotic responses 3. MEOX1 acts as a transcriptional switch controlling the quiescent-to-activated fibroblast transition, with dynamic regulation correlating with cardiac function 4. This mechanism extends beyond cardiac tissue—MEOX1 upregulation occurs in lung, liver, and kidney fibroblasts 4, and MEOX1 is identified as a key gene in cardiac fibroblast activation during hypertrophic cardiomyopathy 1. In neoplastic settings, MEOX1 promotes tumor progression. High MEOX1 expression correlates with lymph node metastasis, advanced stage, and poor prognosis in non-small-cell lung cancer 5. In intrahepatic cholangiocarcinoma, MEOX1 overexpression reprograms regulatory T cells to an immunosuppressive tumor-infiltrating phenotype associated with poor outcomes 6. MEOX1 silencing inhibits prostate cancer cell proliferation while promoting apoptosis 7. These findings position MEOX1 as a therapeutic target in fibrotic and neoplastic diseases.