Original sentence: Poppers have been suggested as a candidate for that cofactor, especially in view of the fact that they are believed to be carcinogenic (Kaposi's sarcoma being a form of cancer).These scientists argue that Kaposi's sarcoma occurs in homosexual AIDS-patients 20 times more often than in non-homosexual AIDS-patients, and that therefore some cofactor must be involved beyond the virus HIV itself
Edited sentence: As Kaposi's sarcoma occur in homosexual AIDS-patients 20 times more often than in non-homosexual AIDS-patients, some cofactor must be involved beyond the virus HIV itself, and poppers have been suggested as the cofactor especially in view of the fact that they are carcinogenic (Kaposi's sarcoma being a form of cancer)