Consistently, the mRNA expression of M1-associated markers (iNOS, TNF-α, and IL-1β) in splenic mononuclear cells was significantly up-regulated in the EAN group (P < 0.05) and down-regulated in the EAN + 4-OI group (P < 0.05, Fig. 2e-g). This evidence concerns the gene IL1B and osteogenesis imperfecta.