It recognizes a transcription factor of 64-67kDa, identified as c-myc. This MAb shows no cross-reaction with v-myc. c-myc is involved in the control of cell proliferation and differentiation and is amplified and/or over-expressed in a variety of tumors. Over-expression of c-myc protein occurs frequently in luminal cells of prostate intraepithelial neoplasia as well as in most primary carcinomas and metastatic disease. Rearrangement of the MYC gene is found in 3% to 16% of diffuse large B-cell lymphoma (DLBCL's) and in nearly 100% of Burkitt lymphomas (BL). Identifying MYC status is important in establishing final diagnosis of DLBCL, BL, or B-cell lymphoma, with features intermediate between DLBCL and BL as well as in differential diagnoses of the lymphomas.