As Biowatch and isolution have mentioned, there are overlapping patents in play. The number of permutations of potential infringement is huge, which makes it difficult for even a patent expert to speculate about how it will all shake out.
Fortunately, it is not essential for investors to forecast the precise outcome of these potential patent disputes because it is unlikely that any company will be severely hampered economically by any of these patents.
-- Regarding OXGN’s new patent announcement (#msg-2061253), I think this is the same patent OXGN mentioned in a PR on 6/26/02: