APOA1 and familial chylomicronemia syndrome: Remarkably, this was associated with ∼50% decreases in both apoC-II and apoE, and modest increases in apoA-I, apoA-II, and apoM, whereas levels of apoB-100 did not change, except in the 3 subjects with familial chylomicronemia syndrome (FCS) (IONIS1), who experienced a marked decrease in TGs (Figure 5A).