Moreover, a recent study has demonstrated that the levels of several PC (16:0/14:0, 16:0/16:0, 16:0/18:3, 16:0/22:4, 16:0e/22:4, 18:0/18:1, 18:0/20:2, 18:1/18:1, and 18:1/20:3) were decreased in cerebrospinal fluid (CSF) from AD patients, suggesting a decline in neuronal and synaptic activity based on the increased PLA2 activity (63). The gene discussed is PLA2G2A; the disease is Alzheimer disease.