This is a map of signaling pathways in a cell. Essentially, how does a cell detect a stimulus and how does the cell respond to it. Signaling networks are notoriously difficult to parse, in major part because many of the proteins that make up the network are promiscuous (meaning that they target many types of proteins instead of just 1). Think of network as less of a series of defined steps and more of a chaotic mess. It's so chaotic that most maps will select a theme (ie, hormone detection, stress signaling, infection, etc.) and only show the interactions that are relevant to that theme. Unfortunately, that also means that each map will show a network that's completely different from the others, even though the proteins are the same.

The joke here is that it's very tempting to make another map. This map is finally going to solve cell biology, I promise, we just have to make another map. Ignore the fact that we already have so many maps, just one more map is all we need