Immunohistochemistry in cancer diagnosis holds great potential to improve patient’s outcomes through enhanced diagnostic accuracy and more effective treatment strategies. Antigen-antibody interactions is one of its main objectives that utilizes the specific binding of antibodies to cellular antigens allowing for the precise identification and localization of specific proteins within tissue samples. However, there exist practical hitches in the form of tissue fixation, epitope retrieval, and antibody quality. It is crucial to continue streamlining the techniques and scoring systems to guarantee their reliability in various contexts. Understanding the interactions is pivotal for the accurate diagnosis, prognosis, and future perspectives. As technology continues to advance and our understanding of cancer biology deepens, immunohistochemistry will remain an invaluable tool for precision in cancer diagnosis.