Table 1.

Sources of Nerve Growth Factor (NGF) and expression of its receptors in human salivary glands and the oral cavity.

Cell Type	Source of NGF/pro-NGF	NGF Receptor Expression
Salivary gland acini	±	±
Salivary gland ducts	+	+
Oral keratinocytes	+	+
Endothelial cells	+	+
Fibroblasts	+	+
Residential leukocytes	+	+
Infiltrating leukocytes	+	+

+ Strong expression; ± weak expression.