The present invention provides methods of treating cancer by administering an IL8-CXCR1 pathway inhibitor (e.g., an anti-CXCR1 antibody or Repertaxin) alone or in combination with an additional chemotherapeutic agent such that non-tumorigenic and tumorigenic cancer cells in a subject are killed. The present invention also provides compositions and methods for detecting the presence of and isolating solid tumor stem cells in a patient (e.g., based on the presence of CXCR1 or FBX021).