CSF2RB and rheumatoid arthritis: Notably, the rule ‘CSF2RB high in RA’ appeared in the independently established rule sets of all analyzed cohorts (rule set ‘Jena’, position 17; rule set ‘Berlin’, position 28; rule set ‘Leipzig’, position 1; and, remarkably, rule set ‘Total’, position 3), again underling the validity of the completely unbiased procedure of rule set generation.