YTHDF2 and systemic lupus erythematosus: The evidence manifested that the mRNA level of PBMC m6A demethylases ALKBH5 positively correlated with that of RNA-binding protein YTHDF2 in patients with AS, which is consistent with the data from Yang et al. (28) and our previous study in systemic lupus erythematosus (SLE) (29).