The invention concerns a wide range of diseases and conditions, includingcancers. The invention provides a probe for detection of such a disease orcondition. The probe is able to distinguish between functional P2X7 receptorsand non-functional P2X7 receptors. The probe can do this in various ways, oneof which is detecting change in relation to binding of adenosine triphosphate(ATP) to the receptors. The invention also provides a method for detecting thedisease or condition, using the probe. The invention extends to treatment ofthe disease or condition, using an antibody, or an epitope capable ofgenerating the antibody, which can distinguish between functional and non-functional P2X7 receptors and bind to the non-functional receptors. Methods oftreatment, pharmaceutical compositions and use of the probe and antibody arealso included.
