1. Needs to add plant, fungal, protist and bacterial signaling components.

2. Needs to add more second messengers

3. Need to add more on secretion, reuptake, destruction mechanism

4. Need to add more on crosstalk, amplification and other network process.

5. Needs to add regulatory strategies such as proteolytic cleavage, phosphorylation, methylation, ubiquitinylation etc

6. Include gene regulation such as operon concept

7. Needs more detail on receptor related topics