Yunis pioneered high-resolution chromosome banding. The more chromosome bands you can see, the easier it is to spot breaks, rearrangements, duplications and other defects in the chromosomes. Yunis placed his pointer next to a band on a chromosome where a break and rearrangement had occurred in the tumor cells of a patient with lymphoma. An oncogene or cancer gene had been found at the break. Then he explained that he had been able to recreate the break in the patient's healthy cells by depriving them of folic acid.
Folic acid is the only vitamin that operates directly on genes.
If you try to grow cells without folic acid in the cell media, or if you treat them with chemotherapeutic agents designed to interfere with folate metabolism, their chromosomes begin to display characteristic breaks, even rearrangements, some involving different chromosomes. That is, a simple vitamin might help keep our genes together. Not molecules like Folkman's endostatin and angiostatin that require a lot of delicate tweaking by structural biologists and biochemists. A simple B-vitamin, discovered in spinach in 1945, and readily available in foods our mothers insisted we finish before we left the dinner table. Also readily available at any drug store.