Immunohistochemistry can be done after a gastric sinus biopsy. For pathological examination, the patient’s gastric sinus biopsy is dehydrated and processed into a wax block, and then sliced on the basis of the wax block for immunohistochemistry examination, and the patient does not need to perform gastroscopy again for re-sampling. Therefore, immunohistochemistry can be performed after a gastric sinus biopsy. Immunohistochemistry uses antigen-antibody reaction to identify antigens in the tissue cells through chemical reaction of the chromogen that labels the antibodies, and to study them qualitatively, locally and relatively quantitatively. Immunohistochemistry enables the determination of the specific origin and direction of differentiation of the tumor tissue. Patients requiring gastric sinus biopsy and immunohistochemistry should actively cooperate with their physicians.