The proportions of genes that are orphams (i.e., single-gene phamilies with no homologues within the mycobacteriophage dataset) are shown for each phage. The order of the phages is as shown in Supplementary file 1. All of the singleton genomes have >30% orphams, and most of the other genomes with relatively high proportions of orphams are the single-genome subclusters (Table 2) including Hawkeye (D2), Myrna (C2), Squirty (F3), Barnyard (H2), Che9c (I2), Whirlwind (L3), Rey (M2), and Purky (P2). Three phages shown in red type are not singletons or single-genome subclusters but have relatively high proportions of orphams. Predator and Mendokysei are members of the diverse and small clusters (five or fewer genomes) H and T, respectively; KayaCho is a member of Subcluster B4 but has a sufficiently high proportion of orphams to arguably warrant formation of a new subcluster, B6.