IFNB1 and infection: shRUNX1 A549 cells and shControl A549 cells were infected with PR8 at an MOI of 5, and then the cells were collected at 0, 3, 6, h.p.i. Compared with shControl cells, the IFNB1 mRNA levels in the shRUNX1 cells significantly increased upon PR8 infection, and increased fold is ~ 4 at 9 h post PR8 infection (Fig. 4a).