 Whether cancer induces modification of TLR9 expression or TLR9 expression hastens the onset of cancer is unclear, but many of the mechanisms that regulate cancer development also play a role in TLR9 expression.DNA damage and the p53 pathway influence TLR9 expression, and the hypoxic environment of tumor cells certainly induces expression of TLR9, further increases proliferation ability of the cancerous cells.Cellular stress has also been shown to relate to TLR9 expression.