Thus, unless indicated otherwise, the general preferences, definitions and examples set out for, e.g. R1 apply also to its sub-groups R1a, R1b R1c etcetera, and similarly with the other R groups.Any references to formula (I) herein shall also be taken to refer to formulae (II) to (VIII) and any other sub-group of compounds within formula (I) unless the context requires otherwise.The term upregulat