LPAR5 and attention deficit-hyperactivity disorder: In contrast, Meijer et al. found differences in methylation of the cholesterol signaling genes APOB (apolipoprotein B gene) and LPAR5 (lysophosphatidic acid receptor 5 gene) in blood samples from individuals with a persistent or remitting ADHD diagnosis, although conclusions about central nervous mechanisms should be treated with caution [37].