A combination comprising: a first agent selected from the group consisting of 2-(1-hydroxyethyl)-naphtho[2,3-b]furan-4,9- dione, 2-acetyl-7-chloro-naphtho[2,3-b]furan-4,9-dione, 2-acetyl-7-fluoronaphtho[2,3-b]furan- 4,9-dione, 2-acetylnaphtho[2,3-b]furan-4,9-dione, 2-ethylnaphtho[2,3-b]furan-4,9-dione and a pharmaceutically acceptable salt or solvate thereof, or a pharmaceutical composition comprising the first agent; and a second agent, for use in: (i) a method of inhibiting a cancer stem cell to treat cancer in a subject, the method comprising administering to the subject a first amount of the first agent to inhibit a cancer stem cell population, and a second amount of the second agent to inhibit a plurality of normal cancer cells; (ii) a method of treating a subject for cancer refractory to a standard treatment, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; (iii) a method of treating or preventing cancer relapse in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; (iv) a method of treating or preventing cancer metastasis in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; or (v) a method of inhibiting a cancer stem cell to treat cancer in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent, wherein the second agent is an anti-cancer agent that is selected from the group consisting of a DNA-damaging agent, an antimitotic agent, and an antimetabolite agent. a first agent selected from the group consisting of 2-(1-hydroxyethyl)-naphtho[2,3-b]furan-4,9- dione, 2-acetyl-7-chloro-naphtho[2,3-b]furan-4,9-dione, 2-acetyl-7-fluoronaphtho[2,3-b]furan- 4,9-dione, 2-acetylnaphtho[2,3-b]furan-4,9-dione, 2-ethylnaphtho[2,3-b]furan-4,9-dione and a pharmaceutically acceptable salt or solvate thereof, or a pharmaceutical composition comprising the first agent; and a second agent, for use in: (i) a method of inhibiting a cancer stem cell to treat cancer in a subject, the method comprising administering to the subject a first amount of the first agent to inhibit a cancer stem cell population, and a second amount of the second agent to inhibit a plurality of normal cancer cells; (ii) a method of treating a subject for cancer refractory to a standard treatment, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; (iii) a method of treating or preventing cancer relapse in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; (iv) a method of treating or preventing cancer metastasis in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; or (v) a method of inhibiting a cancer stem cell to treat cancer in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent, (i) a method of inhibiting a cancer stem cell to treat cancer in a subject, the method comprising administering to the subject a first amount of the first agent to inhibit a cancer stem cell population, and a second amount of the second agent to inhibit a plurality of normal cancer cells; (ii) a method of treating a subject for cancer refractory to a standard treatment, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; (iii) a method of treating or preventing cancer relapse in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; (iv) a method of treating or preventing cancer metastasis in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent; or (v) a method of inhibiting a cancer stem cell to treat cancer in a subject, the method comprising administering to the subject a therapeutically effective amount of the first agent and the second agent, wherein the second agent is an anti-cancer agent that is selected from the group consisting of a DNA-damaging agent, an antimitotic agent, and an antimetabolite agent.