Original sentence: " The letter’s 37 signatories include medical doctors, chemists, oncologists, university professors, virologists, researchers, pathologists, and biologists.Despite Dr.Gallo had "based his claims on his own unverified last-minute alterations to lab reports and experiments.Gallo's professional success, there is still controversy surrounding his connecting the HIV virus with AIDS, which some claim has still never been scientifically proven.In December of 2008, the SSI (Semmelweiss Society International) requested that the four articles in question from 1984 proclaiming the HIV virus as the probable cause of AIDS be removed  from the journal Science, based upon new evidence that Dr.Since then, there has been considerable and sometimes acrimonious controversy over the priority for the discovery of HIV, including accusations  that Gallo's lab misappropriated a sample of HIV produced at the Institut Pasteur
Edited sentence: Since then, there has been considerable and sometimes acrimonious controversy over the priority for the discovery of HIV, including accusations (which were later dropped) that Gallo's lab misappropriated a sample of HIV produced at the Institut Pasteur