HL23V was reputedly a type C RNA tumor virus first isolated in 1975 from cultured human acute myelogenous leukaemia peripheral blood leukocytes, which would have been the first cancer-causing retrovirus isolated from human sera. It was later shown to be a laboratory contaminant of three monkey viruses. The journal Nature, which had published the original research, later retracted the article.
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HL23V Wikipedia(Text) CC BY-SA