HLA-DRB1 and rheumatoid arthritis: Results from our study support the concept that RA development in individuals with familial RA case(s) is associated with a CSA score of ≥3 without including as criteria the presence of FDR and is driven/controlled by the interplay between environmental/behavioral factors (e.g., educational level, childlessness, alcohol consumption, and passive tobacco smoking) and genetic factors (e.g., HLA-DRB1 SE and *07:01).