In the proliferation assay (Figure 3A), the culture supernatants from BC, NC or KD4 cells were used as the source of exogenous KLK7 and the results showed that there was no significant difference between the BC/BC culture supernatant, NC/BC culture supernatant, BC/KD4 culture supernatant and NC/KD4 culture supernatant groups, suggesting that the culture supernatant had no impact on the proliferation capacity of the control PANC-1 cells. The gene discussed is KLK7; the disease is breast cancer.