Exemplary approach to the development of therapeutic agent using PROTAC technology encompassing synthetic organic chemistry, biochemistry, immunology, natural product chemistry and chemical genetics. This book provides with the idea on the role of AHR in human body to survive in this chemical surroundings and the whole process on PROTAC technology which serves as a systematic platform for the development of novel chemical probe which is useful for basic biological researches and further applications in the process of development of new chemical entities.