DNMT3A and Alzheimer disease: The immunohistochemistry results reported here demonstrate that the Histone H3 DNA methyltransferases, DNMT3A and DNMT3B, were up-regulated in response to treatment with alcohol extracts from G. lucidum (Figure 7), indicating that G. lucidum can influence these DNA methyltransferases to regulate the DNA methylation, and that this may be an important signaling pathway influenced by G. lucidum in delaying the progress of AD and/or aging.