Phylogenetic analysis of the CK1 group. Amino acid sequences of the catalytic domain of the CK1 proteins of S. mansoni (blue labels), C. elegans, D. melanogaster, S. cerevisiae, H. sapiens, and B. malayi were used to construct a distance-based phylogenetic tree using PHYLIP programs. Bootstrap values (1000 replicates) equal or higher than 80% are indicated (●) as cutoff values to support the family/subfamily classification. Functional classification is indicated individually in the protein labels. Protein families are highlighted by the vertical bars and include: VRK (Vaccinia Related Kinase), CK1 (Casein Kinase 1), TTBK (Tau Tubulin Kinase), Worm 8 (a specific family of Caenorhabditis), TTBKL (TTBK-Like kinase), and worm 6, two specific families of C. elegans and B. malayi.