Disulfiram caused inhibition of aldehyde dehydrogenases 1 and 2, which, as we have suggested29, leads to the formation from endogenous sources in cancer cells of aldehydes, acetaldehyde and, in particular, formaldehyde, which is known to be two times more effective in killing cancer cells than another substrate of ALDH2, acetaldehyde29,48,49. Here, ALDH2 is linked to cancer.