TOPK is regulated by PP2A and BCR/ABL in leukemia and enhances cell proliferation.

Although treatment of chronic myeloid leukemia (CML) has improved with the development of tyrosine kinase inhibitors (TKIs), patients develop fatal blast crisis (BC) whilst receiving TKI treatment. Alternative treatments for cases resistant to TKIs are required. A serine/threonine protein kinase, T‑lymphokine‑activated killer cell‑originated protein kinase (TOPK), is highly expressed in various malignant tumors.

The tryptophan derivative, tranilast, and conditioned medium with indoleamine 2,3-dioxygenase-expressing cells inhibit the proliferation of lymphoid malignancies.

Indoleamine 2,3-dioxygenase (IDO) is an enzyme that catalyzes tryptophan degradation and induces immunosuppression. Although IDO is an important factor that allows tumors to escape from immunological attack, its effect on lymphoid malignancies has not been fully revealed. We evaluated the expression of IDO in samples from patients with B-cell malignancies.