Graphlet degree centrality. We introduce a new node centrality measure as follows. Graphlets are small, connected, induced, non-isomorphic subgraphs of a large network (Figure 3 A) [46, 47] . Previously, we generalized the degree of a node, that counted how many edges the node touched, into the graphlet degree vector (GDV), that counted how many graphlets of a given type, such as a triangle or a square, the node touched (Figure 3 B) [27] . In Figure 3 B, this is illustrated by a node being touched by an edge (the leftmost illustration), a triangle (the middle illustration), or a square (the rightmost illustration). More precisely, coordinates of a GDV count how many times a node is touched by a particular symmetry group (automorphism orbit, see [47] for details) within a graphlet (Figure 3 B) . Clearly, the degree of a node is the first coordinate in GDV, since an edge is the only 2-node graphlet. There is a total of 73 orbits in all 2-5-node graphlets. Thus, the GDV of a node, describing its up to 4-deep neighborhood (i.e., 2-5-node graphlets around it), has 73 coordinates [27] . An example of a GDV of a node that contains all 73 orbits can be found in [52] .