Bioinformatics or B101nformatics

For biologists using microarrays or sequencing one of the most intersting things is finding if a pathway related to a function is activated or not. To know if a pathway is activated or not usually we need to compare the same pathway in two conditions. It means a subject centered functional scoring method. Which in turns assumes that a pathway is conserved among people and time.   In addition the assumption that is done is that more expression of more genes of a pathways imply an increase of the metabolism of that pathway, which might not be true. Given that pathway has 5 genes, and that all of them are positive regulated implies that a pathway is activated? I have to dive to the origins of this, and see if there is some other way to measure how active a pathway is.

For some time I have been working on one topic. I am not sure if this is how it started but I fail to see other reasons. So I'll describe why I'm now working with gene sets collections. The trigger I usually try to help others in Biostars , Bioconductor , and in the StackExchange network (specially in Bioinformatics ). On one of these sites I was trying to help some person, and in one of the comments ( Jun 21 '17 ) it says: You don't build pathway maps from bioinformatics data, you build them from wet-lab experiments. And I was : " Why not? We already know (kind of) the number of genes, and we have an idea or the number of metabolites in a cell. We have many data, why can't we build pathways?" But I did a brief literature search and I couldn't find anything (if there is something let me know in the comments).   The background Let me explain why this comment got me puzzled: in my work I am usually asked what is the relevan...