Techniques are described to provide multicast service within a virtual network using a virtual network controller and endpoint replication without requiring multicast support in the underlying network. Correlation may require the same characters to be identified a fixed number of times in the same position before acceptance. The invention also relates to the use of the reagent in inhibiting apoptosis and necrosis and in diagnosing a disorder associated with a defect in the function of a Ca2+-binding protein, and in the preparation of a medicament for treating such disorders.