It is known that the macrophage signal transduction leading to TNF-α and IL-1β induction is stimulus-specific with regard to nuclear factor-kappa B (NF-κB) dependence [40-42], and some data support differences in the regulation of TNF-α and IL-1β in RA and in OA, with stronger NF-κB dependence observed in RA [[38,43,44] versus [28]]. This evidence concerns the gene NFKB1 and rheumatoid arthritis.