Direct co-expression relationships such as Penk - Htr 1b, Htr 1b – Sst, and Sst – Oprm 1 which are shown in Figure 2, are corresponded to the excellent role of Penk in combination with the other central nodes such as Htr 1b, Sst, and Oprm 1 in effect of ibuprofen in AD. Here, PENK is linked to Alzheimer disease.