A, Inhibition of proteasome system did not induce ALS formation. Hela cells were treated with 10 μM proteasome inhibitor MG132, 10 μM BITC individually or combined. Both soluble and insoluble fractions were collected and analyzed by immunoblots. B, ALS formation is likely to be triggered by ITC binding to tubulin. HeLa cells were treated with 1 and 10 μM colchicine, 1 and 10 μM vinblastine, 0.1 and 1 μM taxol for 1 h before treated with 10 μM BITC for another 4 h. The insoluble fraction was detected for ALS marker proteins.