Then, we confirmed that the protein levels of ATF6α (p50) and phospho-eIF2αSer51 (Figure 4c), and the mRNA levels of CHOP and GRP78 (Supplementary Figure S6) in HeLa cells with stable SRECA2 knockdown were increased more significantly after exposure to SBF-1, compared with cells with stable NC lentivirus infection. This evidence concerns the gene HSPA5 and lentivirus infection.