KLF4 and Alzheimer disease: However, we found the upregulation of Klf4 in Card9−/−5xFAD microglia analyzed by RNA-Seq and qPCR (Fig. 4 C and D) compelling due to the fact that KLF4 has been shown to regulate microglia-driven neuroinflammation and neuronal loss in the context of AD pathology (72, 73).