1.   These conditions are assumed to have the same final common pathway of biochemical interactions, and lead to a similar series of consequences.

2.   These results therefore support the idea that common evolutionary pathways were involved in the formation of this branch of the MHC gene family.

3.   According to this new hypothesis, addictive drugs like nicotine, heroin and cocaine all work through common pathways in the brain.

4.   But, Horowitz said, there was no common pathway and no way to make sense of the disparate hypotheses.

5.   They build on a growing body of science indicating that many addictions are, at their core, the same, with a final common pathway.