Second, cysteamine (an FDA-approved agent used for the treatment of cystinosis) can be used to inhibit TGM2 and actually prevents the intestinal obstruction that frequently causes the death of mice bearing the CftrF508del/F508del mutation, while it partially rescues the expression and function of the mutant CFTR protein on enterocytes in vivo, phenocopying the effect of the knockout of Tgm2 (refs. 25,54,65). The gene discussed is TGM2; the disease is cystinosis.