MMP9 and Ito hypomelanosis: Additionally, immunohistochemical analyses have revealed augmented expression levels of MMP‐9 and vascular endothelial growth factor (VEGF) in specimens displaying higher nucleolus frequency, nucleus‐to‐cytoplasm ratios, and mitochondrial abundances, reinforcing the notion that the ultrastructural characteristics of IPA cells are intimately linked to their invasive growth patterns.