Daley received his Bachelor of Arts magna cum laude from Harvard College (1982), his PhD in biology from MIT (1989), and his MD from Harvard Medical School, where he was the twelfth individual in the school's history to be awarded the degree summa cum laude (1991).

[5] As a graduate student working with Nobelist David Baltimore, Daley demonstrated that the BCR/ABL oncogene induces chronic myeloid leukemia (CML) in a mouse model,[6] which validated BCR/ABL as a target for drug blockade and encouraged the development of imatinib (Gleevec; Novartis), a magic-bullet chemotherapy that induces remissions in virtually every CML patient.

Daley's studies have clarified mechanisms of Gleevec resistance and informed novel combination chemotherapeutic regimens.

[7] Daley's research seeks to translate insights in stem cell biology into improved therapies for genetic and malignant diseases.

Daley was an inaugural winner of the NIH Director's Pioneer Award (2004), which provides a five-year unrestricted grant to pursue highly innovative research,[9] and received the Judson Daland Prize from the American Philosophical Society for achievement in patient-oriented research,[13] the E. Mead Johnson Award from the American Pediatric Society for contributions to stem cell research,[14] and the E. Donnall Thomas Prize from the American Society of Hematology for advances in induced pluripotent stem cell research, in addition to awards recognizing his contributions to medical research from the National Institutes of Health,[15] the New England Cancer Society, Harvard Medical School, and the Leukemia and Lymphoma Society of America.