EIF2AK3 and neoplasm: Immunohistochemical staining for pERK was performed using a rabbit monoclone on antibody ((D13.14.4E)XP® Cell Signaling Technology) at a dilution of 1 : 100, which demonstrated strong cytoplasmic and nuclear immunoreactivity suggesting MAPK/ERK pathway activation in the majority of tumor cells, including the rosettes (Figure 1f).