CXCL8 and rheumatoid arthritis: Activation of NF-κB is key for the constitutive secretion of IL-6 and IL-8, as well as the secretion of these cytokines induced by IL-1β in FLS-RA (141), which suggests that lactate in the joint could activate intracellular signaling in FLS leading to the expression of pro-inflammatory markers during joint inflammation.