...turned into a horrific mistake. Lucy Willis had observed that folic acid, if administered to nutrient-deprived patients, could restore the normal genesis of blood. Farber wondered whether administering folic acid to children with leukemia might also restore normalcy to their blood. Following that tenuous trail, he obtained some synthetic folic acid, recruited a cohort of leukemic children, and started injecting folic acid into them. In the months that passed, Farber found that folic acid, far from stopping the progression of leukemia, actually accelerated it. In one patient, the white cell count nearly doubled. In another, the leukemia cells exploded into the bloodstream and sent fingerlings of malignant cells to infiltrate the skin. Farber stopped the experiment in a hurry.

Author: Siddhartha Mukherjee