Before revision:  Given the increasing amounts of available BN data of different types, we generalize current homogeneous graphlets to their heterogeneous counterparts, which encompass different node or edge types and thus allow for analyzing a heterogeneous "network of networks". Heterogeneous graphlets will have at least as high impact as homogeneous graphlets have had. We illustrate the usefulness of heterogeneous graphlets in the context of network alignment (NA). While existing NA methods are homogeneous (they can only account for a single node type and a single edge type) , we generalize  a state-of-the-art homogeneous graphlet-based NAmethod into its heterogeneous counterpart.
After revision:  Given the increasing amounts of available BN data of different types, we extend three recent state-of-the-art homogeneous NA methods, WAVE, MAGNA++, and SANA, to allow for heterogeneous NA for the first time. We introduce several algorithmic novelties to achieve this. Namely, these existing NA methods are homogeneous (they can only account for a single node type and a single edge type) , we generalize a state-of-the-art homogeneous graphlet-based NAmethod into its heterogeneous counterpart.