 Scientific studies show that the following cell lines are susceptible to SeV infection to varying degrees.Some of these cells (for example,LLC MK2, 4647 and HEK 293) do not express a protease that processes fusion protein F0 of Sendai virus; therefore, they produce non-infectious virions.Type 1 IFN inhibits the SeV production in normal human respiratory cells, but fails of doing it in human cells that originates from variable malignancies such as U937, Namalwa, and A549.