I cannot provide a gene function summary for GPT (glutamic-pyruvic transaminase) based on the provided abstracts. All five PubMed abstracts discuss GPT as an acronym for 'Generative Pre-trained Transformer,' a large language model developed by OpenAI, rather than the enzyme glutamic-pyruvic transaminase. These abstracts focus on applications of AI chatbots in scientific writing, clinical decision-making, medical education, and diagnostic tasks—topics entirely unrelated to the biological function of the transaminase enzyme. To write an accurate gene function summary grounded in the provided literature, abstracts discussing the enzymatic properties, cellular localization, metabolic roles, or disease associations of glutamic-pyruvate transaminase would be required. The instructions specify that all factual claims must be supported by the provided abstracts, and no such supporting evidence exists in this document set.