PTK2 and cancer: Gene ontology analysis of isoforms exhibiting the top 1000 splice events with the highest variance revealed that these isoforms are enriched for pathways known to be deregulated in GC, such as developmental processes and cell adhesion (gene length bias-adjusted p values 4.9 × 10− 8 and 8.6 × 10− 6) (Fig. 3e), including several known cancer genes such as MADD, PTK2, and NUMA1 (Fig. 3f).