PIK3CD and cancer: But RNA-seq revealed that ZKSCAN1 mRNA mainly regulated cellular metabolism, while circZKSCAN1 mediated several cancer-related signaling pathways, including PI3K pathway, migration pathway, actin cytoskeleton pathway, adhesion pathway and cytokine interaction pathway, suggesting ZKSCAN1 mRNA and circZKSCAN1 may cooperate closely with one another to inhibit growth, migration, and invasion of HCC.