JAK3 and cancer: Studies have shown that upregulation of miR-187 leads to decreased CD276 expression (B7 homologue 3 protein, namely B7-H3, a new member of B7 family immunoregulatory proteins and a promising target for cancer immunotherapy) and inhibits the Janus kinase 3/STAT3/SLUG (JAK3/STAT3/SLUG) signaling pathway, It has been demonstrated that BMMSCs-Exo carrying miR-187 can inhibit the progression of prostate cancer through targeting CD276 and the JAK3/STAT3/SLUG axis (Figure 4).