PPP4R2 and Parkinson disease: PPP4R2 and PPP1CC code for enzymes in the serine/threonine-protein phosphatase family and are well-known contributors to canonical Alzheimer’s disease pathological cascades.67 Interestingly, PPP4R2 has also been identified as a top hypomethylated gene of interest in a methylome-wide association study of Parkinson’s disease,68 an illness which is also often accompanied by cognitive decline.69 Other top contributors to the three-modal subtypes, such as PSMD11,70APBB271 and TMEM253,72 are also known to be involved in the development of Alzheimer’s disease pathology.