This paper comments on Jan Faye's metadisciplinary characterization of the notion of causation. I will argue that his understanding of a causal factor as a difference-maker can be specified by relating it to similarity considerations and analogical reasoning about causal dependencies. At the same time, however, his notion of a difference-maker does not capture what is understood as a cause in many biological and biophysical investigations of robustness of living systems (e.g. in systems biology). Finally, I will show that Faye ignores crucial differences between causal processes and causal mechanisms.