CREB1 and Alzheimer disease: Similarly, in the second study case, we found that the differentially expressed (such as VDR [60], SP1 [61], CREB1 [62], and RELB [63]) and the non-differentially expressed (such as ESR1 [64], PPARG [65], ESR2 [66], and PPARD [67]) genes are AD-related genes.