CD274 and colorectal cancer: Similarly, hypoxia-induced exosomes containing circRNA 133 (circ-133) and circRNA eukaryotic translation initiation factor 3 subunit K (circEIF3K) can be transported to normoxic colorectal cancer (CRC) cells via the activation of the miRNA 133/Global H1/Ras homolog family member A (miR133a/Global-H1/RhoA) and miRNA 214/PD-L1 (miR-214/PD-L1) axes, respectively, to promote the proliferation and migration of CRC cells (51, 52).