CYP1B1 and nasopharyngeal carcinoma: To back up our suspicions, we used qRT-PCR to test the mRNA expression of the three and discovered that the level of SCARB1 was significantly higher in NPC cell lines than in macrophages (Fig. 2N), whereas HAAO was highly expressed in M1 macrophages and CYP1B1 in M2 macrophages (Fig. 2N).