According to RT-PCR bands shown in Figure 4(a), the ulinastatin group had markedly decreased mRNA levels of ERK and FOXO3 in breast cancer cells compared with the control group (∗p < 0.05, ∗p < 0.05), and the ulinastatin+ERK inhibitor group exhibited obviously reduced mRNA levels of ERK and FOXO3 in breast cancer cells compared with the ulinastatin group (#p < 0.05, #p < 0.05), indicating that ulinastatin is capable of repressing the mRNA expressions of ERK and FOXO3 in the ERK signaling pathway. This evidence concerns the gene FOXO3 and breast cancer.