There aren’t too many other blogs that we’d characterize as “essential” to what we do, but the FDA Law Blog is one of them (SCOTUSblog is another). Yesterday’s post (emailed this morning) on the FDA Law Blog about a new draft FDA guidance concerning certain investigational in vitro diagnostic devices may seem arcane at first glance, but it describes an FDA regulatory departure with potentially far reaching implications – maybe even a renewed attack upon off-label use on a scope not seen since the nadir of the Kessler commissionership in the mid-1990s.