THE INVENTION CONCERNS A WIDE RANGE OF DISEASES AND CONDITIONS, INCLUDING CANCERS. THE INVENTION PROVIDES A PROBE FOR DETECTION OF SUCH A DISEASE OR CONDITION. THE PROBE IS ABLE TO DISTINGUISH BETWEEN FUNCTIONAL P2X7 RECEPTORS AND NON-FUNCTIONAL P2X7 RECEPTORS. THE PROBE CAN DO THIS IN VARIOUS WAYS, ONE OF WHICH IS DETECTING CHANGE IN RELATION TO BINDING OF ADENOSINE TRIPHOSPHATE (ATP) TO THE RECEPTORS. @@THE INVENTION ALOS PROVIDES A METHOD FOR DETECTING THE DISEASE OR CONDITION, USING THE PROBE.@@THE INVENTION EXTENDS TO TREATMENT OF THE DISEASE OR CONDITION USING AN ANTIBODY OR AN EPITOPE CAPABLE OF GENERATING THE ANTIBODY , WHICH CAN DISTINGUISH BETWEEN FUNCTIONAL AND NON-FUNCTIONAL P2X7 RECEPTORS AND BIND TO THE NON-FUNCTIONAL RECEPTORS. @@METHODS OF TREATMENT, PHARMACEUTICAL COMPOSITIONS AND USE OF THE PROBE AND ANTIBODY ARE ALSO INCLUDED.