With a focus on treatment and prevention of colorectal cancer, Dr. Zell serves as a gastrointestinal (GI) medical oncologist and translational oncology researcher at the UC Irvine Chao Family Comprehensive Cancer Center. At UC Irvine, he is Vice Chief for Academic Affairs in the Division of Hematology/Oncology and Program Director for the ACGME-accredited Hematology/Oncology fellowship training program. He serves as national Principal Investigator for SWOG 0820: PACES "Preventing Adenomas of the Colon with Eflornithine and Sulindac", a phase III double blind-placebo-controlled clinical trial launched through the NCI-National Community Oncology Research Program (NCORP). Dr. Zell currently serves as co-Chair of the NCI Gastrointestinal Committee’s Rectal/Anal Task Force and is Member of the NCI's Cancer Prevention Steering Committee.