DKK1 and rheumatoid arthritis: Small interfering RNA has been employed to block Dkk-1 and exhibit neuroprotection in a model of intracerebral haemorrhage [67], inhibit inflammation in a model of rheumatoid arthritis [68], and in a model of hormone deficiency-induced bone loss [69], but to the best of our knowledge, this is the first demonstration of the use of a Dkk-1 targeting vivo morpholino to treat experimental malignant bone disease.