Fig. 4: High expression of phosphorylated Nrf2 (p-Nrf2) is associated with overall survival and disease-free survival in patients with oral squamous cell carcinoma (OSCC).

A–D Representative images of immunohistochemical staining of p-Nrf2 are presented according to its expression (original magnification, ×200). Tissues were immunohistochemically stained using antibodies specific for p-Nrf2 (Ser40). A Human normal placental tissue (positive control). B Human normal placental tissue (negative control). C A patient exhibiting high-intensity staining for p-Nrf2. D A patient with low-intensity staining for p-Nrf2. Bar, 50 µm. E, F The Kaplan–Meier curves of 110 patients with OSCC based on p-Nrf2 expression. Patients with OSCC were divided into two groups based on their p-Nrf2 expression status (p-Nrf2-low vs. p-Nrf2-high). E Overall survival. F Disease-free survival. *p < 0.05. G, H OSCC tissue samples stained with p-Nrf2 using immunohistochemistry. G There was no expression of p-Nrf2 in biopsy samples acquired before chemoradiotherapy (CRT). H Cells resistant to CRT express p-Nrf2 in the primary lesion. Original magnification, ×200; bar, 50 µm.