From laboratory-grown cannabis roots, scientists have extracted nanoscale particles that appear to rouse the immune system and slow tumor growth in mice — a quiet but methodical step in the long human effort to enlist the plant kingdom in the fight against cancer. The work, published in NPJ Science of Food, does not claim a cure; it claims a credible beginning. What it offers is a reproducible platform, a coherent biological mechanism, and a set of honest questions worth pursuing.