The present invention provides methods relating to chemotherapeutic treatment of a cell proliferative disorder. In particular, a method is provided for predicting the clinical response to certain types of chemotherapeutic agents. Alkylating agents, used for the treatment of certain types of tumors including tumors of the nervous system and lymph system, are efficacious agents when the damage they do to tumor cell DNA is not repaired by cellular DNA repair mechanisms. The present invention provides a method for determining the activity of a gene encoding a DNA repair enzyme, thus providing a prediction of the clinical response to alkylating agents.