The results of fluorescence co-localization (Fig. 3B) showed that under hypoxia, EGFP-LC3 appeared obvious punctate and granular in RA-FLSs, which was one of the typical characteristics of autophagy induction, and the morphology of mitotracker mitochondria showed no significant change compared with that of normoxia, but the co-localization of mitotracker labeled mitochondria and EGFP-LC3 labeled autophagosomes increased, It indicated that hypoxia induced the occurrence of mitophagy. The gene discussed is MAP1LC3A; the disease is rheumatoid arthritis.