During the last decade research is gradually repositioning the antimalarial drug chloroquine, and certain related
quinoline derivatives, as anticancer agents. Chloroquine and hydroxychloroquine, in particular, have relatively wellcharacterized
toxicity profiles due to several decades of use for treatment of malaria. Previously published review articles
provide an excellent overview of the diversity of chloroquine effects on cancer cells, both in the cell culture as well as on
human tumors grafted into mice; and an account of the increasing pace of incorporation of hydroxychloroquine in combination
treatment schemes for clinical studies. In this review we present some features that are common between cancers
that are sensitive to quinoline derivatives, in particular features that are amenable to pharmaceutical intervention.