Transcriptional regulation of the SUMOylation pathway by Myc is mainly direct. (A) P493-6 B cells carry a Tet-repressible MYC gene.²⁵  Upon Tet treatment, the expression of Myc is reduced to nearly undetectable levels, and following withdrawal of Tet, Myc levels are restored within hours. Shown is the transcript expression of the indicated components of the SUMOylation pathway upon Myc activation (GSE40782). (B) Myc immunoblotting upon incubation of P493-6 cells with Tet (24 hr) and subsequent washout (-Tet 24 hr). (C) qPCR analysis of the indicated transcripts in P493-6 cells. Labeling of x-axes: 0, 0 hours Tet; 1, 24 hours Tet; 2, 24-hour Tet withdrawal (n = 3). (D) To assess direct Myc regulation, 2 publicly available quantitative ChIP-seq analyses were consulted.^35,36  Shown is a summary of direct Myc binding to E-box sequences. X indicates direct Myc target genes.