Consistent with previous findings that promoting ferroptosis of RA-FLSs improves RA, the results of a recent study also indicate (117) that glycine drives ferroptosis of RA-FLSs through methylation of the S-adenosylmethionine (SAM)-associated GPX4 promoter and further enhances this effect by reducing FTH1 expression. Here, GPX4 is linked to rheumatoid arthritis.