Overall, miR-15a carried by adMSCs-Evs has the potency to maintain H3K27me3 expression and to inhibit HOXC4 transcription by targeting KDM4B in CRC cells, thereby reducing PD-L1 expression and finally inhibiting immune evasion in CRC cells (Figure 7F). The gene discussed is KDM4B; the disease is colorectal carcinoma.