Perls stain and ferritin expression. (A) FGF-6 protein level was evaluated by IHC assay (IHC) in skin tissues from SSc patients and healthy controls (Normal). Staining was visualized by Nikon microscopy; original magnification ×200. A Student t test was used to test for pairwise differences between AOD values between SSc and normal observations. The ratio of positive stain areas to the total area was used to evaluate protein levels. AODs were quantified by ImageJ software. **P < .01. (B) IHC with Perls Prussian Blue stain for ferritin protein was applied to evaluate the iron deposition in SSc skin tissues and healthy skin tissue. AOD values were quantified by ImageJ software. Staining was visualized by Nikon microscopy; original magnification ×200. **P < .01. (C) IHC of FGF-6 protein in liver cancer tissue and control tissue. AODs were quantified by ImageJ software. Staining was visualized by Nikon microscopy; original magnification ×200. *P < .05. (D) IHC of ferritin protein using Perls Prussian Blue stain in liver cancer tissue and control tissue. AODs were quantified by ImageJ software. Staining was visualized by Nikon microscopy; original magnification ×200. *P < .05.