Higher levels of Cystatin C (CysC) were positively associated with all three atrophy measures after adjusting for baseline brain volumes and t-tau and remained predictive of higher whole brain (P=0.009) and hippocampal atrophy (P=0.034) after adjusting for p-tau, age, ApoE status and sex. This evidence concerns the gene CST3 and hippocampal atrophy.