The Fanconi anemia (FA) pathway is a complex phosphorylation-ubiquitination network in the DNA damage signaling, which is still poorly understood. Defects in the "FA pathway" or in the related DNA repair proteins cause FA, a hereditary disorder that accompanies compromised DNA crosslink repair, poor hematopoetic stem cell survival, genomic instability, and cancer. For molecular dissection of the FA pathway, we have been using chicken B cell line DT40 as a model system. In this review, we will summarize our current understanding of the pathway, and discuss how studies using DT40 have contributed to this rapidly evolving field.