UAS regulatory sequences drive expression of 4 sgRNAs (TGGTCGTCCATTATGGAATACGG, CTTCTCGAGATCACTCTGAATGG, GAGGTCCATTTAATACCGCCCGG and CTATCAGAGCCGGTCGTCGGCGG), each of which targets Myc. The sgRNAs are expressed as a single polycistronic tRNA-gRNA cassette.