Abstract
We wish to thank members of Zhang lab for valuable discussions and Dr. Joseph
Biggs for critical editing. This work was supported by research funding from National
Institutes of Health (GM066955 & CA102625). The Stein Endowment Fund has
partially supported the departmental molecular biology service laboratory for DNA
sequencing and oligonucleotide synthesis. This is manuscript 19372 from The Scripps
Research Institute.