Interestingly a CRMO-like presentation is also seen in SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) and in the monogenic mimics Majeed Syndrome (LPIN2 mutation) and Deficiency of Interleukin-1 Receptor Antagonist Syndrome (IL1RN mutation). The gene discussed is IL1RN; the disease is Majeed syndrome.