As shown in Figure 1(a), compared with that in the control group, the expression of p-PERK, p-elf2α, and ATF-4 was significantly increased in the IH group; however, the expression of ATF-6 and p-IRE1 did not increase after 2 weeks of IH exposure. This evidence concerns the gene EIF2AK3 and isolated hemihyperplasia.