Sir, the publication “Mosaic pancreas or type 3 diabetes: how do we define it?” is very interesting [1]. Irving et al. reported this interesting situation and proposed to name it as Mosaic Pancreas or type 3 diabetes [1]. The mentioned situation [1] is interesting and might be classified as a new kind of diabetes. However, the term type 3 diabetes is not a new one. This is already the specific medical term used for describing diabetes mellitus with Alzheimer’s disease [2]. In brief, type 3 diabetes has already been well used for Alzheimer’s disease which results in the insulin resistance in the brain for a long time. The idea that Alzheimer’s might be type 3 diabetes was proposed by Dr. Suzanne De La Monte in 2005 [3]. Since then, over 20 papers have proposed this idea which is also accepted by clinicians [2, 4]. The type of diabetes reported by Irving et al. is an atypical diabetes between type 1 and type 2 diabetes, which has nothing to do with the Alzheimer’s disease. Hence, if Irving et al. would like to set a new classification, this situation should be named as “diabetes type 4.”