The head of the Centers for Disease Control and Prevention resigned Wednesday morning after an investigation revealed that she had bought tobacco stocks shortly after assuming a job that put her in charge of promoting health across the country. Brenda Fitzgerald, who has led the CDC under President Donald Trump for the past six months, resigned because “certain complex financial interests that have imposed a broad recusal limiting her ability to complete all of her duties as the CDC Director,” Department of Health and Human Services spokesman Matt Lloyd said in a statement on Wednesday.