We found that sEV-CD44 derived from LNM-GC cells increased FAO activity in BM-MSCs through activating ERK/PPARγ/CPT1A signaling pathway, thereby leading to IL-8 and STC1 secretion to facilitate LNM by enhancing GC cells migration, invasion and lymphangiogenesis as well as inducing cellular and sEV CD44 expression to form positive feedback loop between GC cells and BM-MSCs (Fig. 8). Here, CPT1A is linked to gastric cancer.