CD47 and cancer: In addition, the surface expression of CD47 prevents the clearance of exosomes by monocytes and macrophages.[51] Recently, a number of therapeutic exosomes that deliver RNAi drugs have been reported to inhibit the growth of cancer.[51, 52, 53] Thus, we attempted to establish an exosome‐based delivery system loaded with the siRNA against BRIX1 for the treatment of cancer.