HMOX1 and Alzheimer disease: MSCs from adipose tissue (AD-MSCs) can also convert detrimental microglia phenotypes into neuroprotective phenotypes, as identified by a reduction in the expression of pro-inflammatory factors and an induction of neuroprotective and anti-inflammatory markers, of which Nrf2/HO-1 signaling and TNF-stimulated gene 6 protein in AD-MSCs seem to play a crucial role (Neubrand et al., 2014; Jha et al., 2019; Huang et al., 2020).