This mutant was used as a model mimicking the physiological situation in tumours, in which shedding of CA IX might be hampered due to the absence of ADAM17, its inactivation by TIMPs-mediated inhibition, its aberrant maturation and activation, or due to somatic mutations affecting the CA IX folding and interaction with the proteinase.46,47. This evidence concerns the gene ADAM17 and neoplasm.