IARS1 and vulvar carcinoma: The MTA1 staining process in the cytoplasm showed a weak color reaction (IRS 1–2) in 28.6% of the vulvar carcinoma tissue sections, 61.1% showed a moderate color reaction (IRS 3, 4, 6), whereas 4.8% of the specimens showed a strong color reaction (IRS 8, 9, 12) of MTA1.