Immunohistochemistry for Inhibin (usually Inhibin-α) is a diagnostic stain used to detect the expression of inhibin protein in tissue sections. Inhibin is a glycoprotein hormone produced mainly by gonadal stromal cells, particularly ovarian granulosa cells and testicular Sertoli cells.

This marker is commonly used in surgical pathology to help identify and characterize tumors of sex cord–stromal origin, especially in the ovary and testis. It is also useful in differentiating these tumors from other neoplasms, such as epithelial tumors or metastatic lesions.