Yet, existing corpora differ greatly in size, thematic focus, annotation quality, granularity of the underlying conceptual entity representation and the way individual entity classes are defined-even when different corpora cover the same entity classes.
merging all available annotations into one large corpus and regard it as a coherent source of gene/protein annotations (Wang et al., 2009;Wang et al., 2010;Galea et al., 2018) might not be advisable.