Methods for treating breast and bladder cancer patients based upon E2F4 regulatory activity as a predictor of relapse of a patient with estrogen receptor positive breast cancer and in bladder cancer stratification are provided. The methods involve determining gene expression profiles for substances linked to activity of E2F4 in cancer cells and tissue. Signature gene expression profiles are provided for identifying breast cancer samples and bladder cancer samples that would be responsive to certain therapies and also provide for prognosis based on these profiles.
