In our study, increased expression of p16INK4a, an irreversible cell-cycle arrest marker (Fig. 7A and D), and TNF-α, a pivotal pro-inflammatory cytokine (Fig. 8C–E), were identified in Iba1+ microglia within the BF of AD mice indicating an acquired SASP (senescence-associated secretory phenotype). Here, TNF is linked to Alzheimer disease.