We examined the expression of Ki-67 in tumor cells and the serum lactate dehydrogenase (LDH) levels of 13 patients and compared them among the following three groups; aggressive ATL (n = 4), HTLV-1 AC and indolent ATL (n = 4), and other lymphoid malignancies (n = 5) (Fig. 2D). This evidence concerns the gene MKI67 and neoplasm.