Recently, we observed that histone acetylation and crotonylation mediated the expression of endocytosis-related genes and tumor-related immune checkpoint genes by regulating the enrichment of signal transducer and activator of transcription 3 on these gene promoters in Alzheimer’s disease and tumorigenesis, suggesting that histone modification plays an important role in disease development. The gene discussed is STAT3; the disease is neoplasm.