Previously, it was published that the SET8 protein methlytransferase methylates the Numb protein. This result was not in agreement with an earlier study of our group regarding the specificity of SET8. In this new paper we show in a detailed biochemical study that SET8 does not methlyate the Numb protein. This is an improtant finding, becasue via p53, SET8 and Numb have important roles in carcinogenesis.