Abstract: The present invention contemplates a method to identify subjects that either have a tumor, or are at risk for tumor development, that are responsive to various inhibitors of an activated-Chk2 protein. Such Chk2 inhibitors may comprise a benzimidazole core structure, and derivatives thereof. Other Chk2 inhibitors may comprise nucleic acids, such as silencing interference RNA's specific for a Chk2 expression. Other Chk2 inhibitors may comprises proteins, such as antibodies. For example, the present invention contemplates that when a Chk2 inhibitor is administered during, or after, ionizing radiation tumor cell apoptosis is increased.