The father of the dominant theory of Alzheimer’s disease told another eminent researcher he is “causing harm” by criticizing his theory in an email obtained by the Daily Caller News Foundation.

For three decades University College London neurogeneticist John Hardy and like-minded scholars have been so dominant in promoting the theory that amyloid-beta plaques are the root cause of Alzheimer’s that some journalists and critics have referred to proponents as the “amyloid mafia.”

But recent high-profile retractions and allegations of fraud in hundreds of other papers have threatened to undermine the clique’s supremacy. None of Hardy’s work has been retracted, but he has cited papers with evidence of image manipulation in 58 of his papers.

He is not alone: 77,655 Alzheimer’s papers cite the hundreds of papers compromised by manipulated evidence, according to a February book by Science reporter Charles Piller. Forty-six Alzheimer’s researchers, including major contributors to the amyloid hypothesis, have authored papers with evidence of manipulated data.