tokens: However , during our work with a replication deficient virus expressing the ASF / SF2 splicing factor from a progesterone antagonist inducible gene cassette , we discovered that ASF / SF2 was expressed at a significant level in the 293 producer cell line , even in the absence of inducer .
folded_tokens: however , during we work with a replication deficient virus express the ASF / sf2 splicing factor from a progesterone antagonist inducible gene cassette , we discover that ASF / sf2 be express at a significant level in the 293 producer cell line , even in the absence of inducer .