Summary: Finally, in Chapter 5, I comment on the potential of Kin28/CDK7-based therapies for the treatment of disease, and how studies in yeast can inform on the mechanism of action of such therapies. Appendix I describes my efforts into characterizing the role of CTD methylation on gene expression. In sum, this work has significantly contributed to our understanding of the myriad ways Kin28/CDK7 functions in regulating gene expression beyond its canonical roles in promoting RNA synthesis.