Samples of a juxtaoral organ were examined immunohistochemically with antibodies against light-chain cytokeratin (KL-1), cytokeratin 19, desmin, chromogranin, neuron-specific enolase, and S-100 protein. The epithelial cells were found to be immunoreactive only with the two cytokeratin antibodies. Transmission electron microscopy was also performed. The results are best compatible with a mechanoreceptor function of the organ.