APOE and early-onset autosomal dominant Alzheimer disease: Data from clinical trials illustrated that the intervention with medium‐chain triglycerides increased blood levels of lysoPCs (e.g. 16:0, P‐18:0, P‐18:1[9Z], 20:2[11Z,14Z] and 22:5[4Z,7Z,10Z,13Z,16Z]), as the part of positive effects on cognitive ability in mild to moderate Alzheimer's disease patients without APOE4.63