CRISPR technology has revolutionized the field of genome engineering. CRISPR allows for the easy and efficient manipulation of virtually any genetic locus through a two-component system: a CRISPR endonuclease and guide RNA (sgRNA). These components form a complex that enacts double strand breaks in target DNA. The repair of the double strand break is the main mechanism by which genetic editing of a locus takes place. While the endonuclease cleaves target DNA, it is the sgRNA that specifies targets through complementary binding to a target site. Determining the specificity of sgRNAs to their target site represented a crucial challenge to the genome-engineering field. To facilitate the design of CRISPR libraries, we developed Guidescan, a software package that allowed for the customizable production of sgRNA databases that were guaranteed to match user-defined requirements for sgRNA uniqueness. Furthermore, several computational studies of leukemia are described in this thesis that illustrate different molecular actors and mechanisms through which a leukemic like disease, Myelodysplastic Syndrome, can progress towards leukemia, how leukemia hijacks a splicing protein to maintain its pathology, and finally, how a leukemia can develop resistance to a targeted therapy.