Everything that affects your body, from the most mundane things to those that are life-threatening, work through intracellular signaling mechanisms. Therefore, it is vitally important for you to understand how your cells respond to the signals they receive. Unfortunately, the flat 2-dimensional drawings typically used in textbooks do not convey the "dynamic" nature of these processes, causing many students to struggle to understand cell signaling. In most cases, this problem arises because it can be difficult to envision the different components involved and where things take place in the cell. As a result, the majority of students simply memorize the information for an exam and then forget it immediately. This ebook addresses that problem first by putting you on the cell surface where you can see a ligand interact with its receptor, and then taking you inside where the dynamic nature of intracellular signaling becomes apparent. Within this context, cell signaling will finally make sense, taking you to the point where you can actually apply your new knowledge rather than just lose it.