What is the difference between genetic cross regulation and crosstalk? I'm a physics major and learning about bioinformatics now. So it might seem trivial to many but from the article "Wanner BL. Minireview. Is cross regulation by phosphorylation of two component response regulator proteins important in bacteria? J Bacteriol 1992; 174:2053-8." I could not find a quantitative way to separate these two kind of gene regulations. Also, I would appreciate if anyone can suggest me something to read for further knowledge on this topic. Thanks!