To determine if NOD2 with a Blau mutation retains the cross-regulatory function of WT NOD2, we first conducted studies of TNBS-colitis in mice with transient over-expression of WT NOD2, Blau syndrome (BS)-NOD2 (bearing the NBD mutation: R314W), and CD-frameshift NOD2 (FS987). The gene discussed is NOD2; the disease is Blau syndrome.