Suppressor of Mek1 (Smek1, also known as PPP4R3A), a regulatory subunit of serine/threonine‐protein phosphatase 4 (PP4), is a conserved protein that participates in various biological processes.[5] A GWAS indicated that PPP4R3A rs2273647‐T is related to disease risk and progression in Alzheimer's disease.[6] The authors determined that the minor allele (T) dosage was significantly associated with a reduced probability of developing mild cognitive impairment (MCI) or AD and modified the extent of cognitive decline over time. Here, PPP4C is linked to Alzheimer disease.