Moreover, we demonstrated that exogenous production of HtrA4 and ∆N-HtrA4 attenuated the clonogenic potential (Figure 6A) and motility (Figure 7A) of cancer cells treated with etoposide, and it modulated the cell cycle by enhancing arrest of the cells in the G2/M phase (Figure 8A, Table 3). Here, HTRA4 is linked to cancer.