CDX1

CDX1, or Caudal-type homeobox 1, is a transcription factor encoded by the human CDX1 gene. It belongs to the caudal-type homeobox (CDX) family and contains a homeodomain that mediates DNA binding. CDX1 is expressed in the developing gut and in the adult intestinal epithelium, where it contributes to hindgut identity and to the differentiation of intestinal epithelial cells.

In vertebrates, CDX1 cooperates with related CDX factors to establish regional intestinal identity and regulate expression of genes required for intestinal function. CDX1 functions by binding promoter and enhancer regions and activating or repressing target genes involved in differentiation and proliferation. Its activity is integrated with signaling networks such as Wnt/β-catenin and interacts with other transcription factors to refine cell fate.

CDX1 expression is developmentally regulated and remains part of maintained gut homeostasis in adults. Altered CDX1 expression has been observed in gastrointestinal cancers. In colorectal cancer, reduced CDX1 expression has been reported in some tumors and has been associated with poorer differentiation and prognosis in certain studies, suggesting a possible tumor-suppressive role, though findings are not entirely consistent.

In research, CDX1 serves as a marker of intestinal lineage and is studied in mouse and cell models to understand gut development and epithelial differentiation.