Raf kinase inhibitor protein combined with phosphorylated extracellular signal-regulated kinase offers valuable prognosis in gastrointestinal stromal tumor

Figure 1 Immunohistochemical staining. A: Immunohistochemical staining for raf kinase inhibitor protein (RKIP) in gastrointestinal stromal tumor (GIST) tissues; B: RKIP protein showed positive expression in the cytoplasm and cell membrane, appearing as brownish-yellow or brown granules; C: Immunohistochemical staining for phosphorylated-extracellular signal-regulated kinase (P-ERK) in GIST tissues; D: P-ERK protein exhibited heterogeneous distribution in GIST cells, mainly in the cytoplasm, with occasional presence in the nucleus, and appeared as brownish-yellow granules; E: Immunohistochemical staining for phosphorylated-mitogen-activated protein kinase/ERK Kinase (P-MEK) in GIST tissues; F: P-MEK protein expression in GIST cells was observed as brownish-yellow granules, mainly distributed in the cytoplasm, with some in the nucleus, and showed a relatively uniform distribution. A, C and E were taken under 200 × magnification.