Tax on the net income of an individual, organization, or business.

Legally authorized corporations owned and managed by one or more professionals (medical, dental, legal) in which the income is ascribed primarily to the professional activities of the owners or stockholders.

Revenues or receipts accruing from business enterprise, labor, or invested capital.

Transcriptional trans-acting proteins of the promoter elements found in the long terminal repeats (LTR) of HUMAN T-LYMPHOTROPIC VIRUS 1 and HUMAN T-LYMPHOTROPIC VIRUS 2. The tax (trans-activator x; x is undefined) proteins act by binding to enhancer elements in the LTR.