APOC1 and neurodegenerative disease: GWAS of possible preclinical neurodegenerative disease blood biomarkers of caspase‐3‐cleaved (TAU‐C) and ADAM‐10 cleaved tau (TAU‐A) found only one significant SNP for each of these biomarkers: APOC1 (rs10414043) for TAU‐A and APOE (rs429358) for TAU‐C.41