UBC and cancer: Our pathway enrichment analyses (Fig. 2c) revealed the following pathways were enriched in at least three cancer types: (i) protein homeostasis (protein processing in endoplasmic reticulum, ubiquitin-mediated proteolysis), (ii) cell-cell interactions and morphology (regulation of actin cytoskeleton, focal adhesion), (iii) RNA homeostasis (spliceosome, RNA transport), (iv) cancer-related signaling pathways (pathways in cancer, MAPK signaling pathway), and (v) others (neuroactive ligand-receptor interaction, endocytosis).