APOE and Parkinson disease: A recent GWAS study has been published based on the TD and PIGD motor subtypes which found multiple PD risk alleles that might influence the motor subtype.12 We have recently published a GWAS study using data from the Oxford Discovery, Tracking Parkinson’s and PPMI cohorts to look at motor and cognitive progression which found that APOE ε4 influences progressive cognitive impairment.13 This study differs to our previous one as its focus is on data-driven PD subtypes.