Neighbor-joining tree. Illustrated are 1388 IAPLTR_Mm elements drawn from the C57BL/6 genome and including Avy and CabpIAP elements for a total of 1390. Subclades are highlighted in red (clade 1) and green (clade 2), with the remaining elements in black (clade 3). The bifurcation of subclades 1 and 2 demonstrates duplication and divergence events followed by rapid radiation of these subfamilies. Scale bar indicates number of nucleotide substitutions per site.