Have been discussing this with a few friends of mine. Is the order of co-first authors important in a manuscript? I was told that, if the list of author order is AAA*, BBB*, CCC,DDD,EEE, with * denotes equal contribution, regardless of co-authorship or not, AAA is still the Main leader of this project? My question is, if that is the case, what is the point of having a co-first annotation ?