HIF1A and rheumatoid arthritis: 1) Reveal the hypoxia mechanism of RA tissues and cells: Through single-cell sequencing, proteomics, and gene knockout technology, the interaction mechanism of HIF-1α on downstream signaling pathways and its temporal and spatial dynamic changes in the hypoxic microenvironment of RA was deeply explored, which provided a new perspective and new ideas for the development of new diagnostic biomarkers and the determination of new therapeutic targets.