I was scanning through my book Tripping over the Truth and on page 47-48 this is an exact quote:

In the summer of 1946, Fabers first attempt to develop a chemotherapy drug worked in spite of himself.  Learning that folic acid (folate) could treat anemia, he sloppily reasoned that because the vitamin exerted its effect on blood production, maybe it would, somehow, push the overproduction of blood in leukemia patients toward normality.  But Farber soon found that his logic was exactly backward.  The vitamin was required for DNA to replicate, to give it to a leukemia patient was to pour gasoline on a fire.  Once injected, the patient’s cell counts exploded, violently accelerating the disease

http://www.myelomabeacon.com/resources/mtgs/ash2013/abs/4436/

Role Of Folate Receptor Targeted Therapy In Multiple Myeloma

In multiple myeloma (MM) the interaction of plasma cells, bone marrow stromal cells and tumor associated macrophages (TAMs) plays a significant role in conferring resistance to therapy and in the maintenance of residual disease. Folate receptors (FR) are specifically expressed on metabolically active malignant cells and TAMs and their expression in normal tissues and resting macrophages is limited. FR mediates folate uptake by receptor-mediated endocytosis. This qualifies the receptor to be exploited for drug delivery of folate conjugated cancer therapeutics.

Green tea may work by EGCG acting as folate scavenger.