Biostatisticians Keith Baggerly and Kevin Coombes, like many, were intrigued by claims of personalized chemotherapy treatments by geneticist Anil Potti in 2006. Then at Duke University in Durham, North Carolina, Potti published results indicating that gene expression signatures could identify which chemotherapy drug could best treat lung or breast cancer — results that led to the setup of three clinical trials. But Baggerly and Coombes quickly found something amiss in the data. What began as concerns over apparent errors, including mislabelled samples and mismatched gene names, eventually snowballed into one of the most notorious cases of scientific misconduct in the United States in recent years.