Western blot using anti-FANCF antibody shows detection of FANCF present in a lysate prepared from a Fanconi anemia complementation group F patient lymphoblast after retroviral correction using hFANCF cDNA (lanes 3 and 4). This band (indicated by arrowhead) is approximately 42.3 kDa in size. The band is not detected in FA-F a lymphoblast lysate that is not corrected for the deletion and does not express the FANCF protein (lanes 1 and 2). Lanes 2 and 4 represent lysates taken from lymphoblasts after 40 J/m2 UV irradiation, whereas lanes 1 and 3 received no irradiation. No apparent difference was noted upon irradiation. The strong band at ~60kDa appears to be non-specific. Personal communication, N. Howlett, University of Rhode Island, Kingston, RI.