Recent research has revealed a variety of circRNAs involved in PC progression and GEM chemoresistance, such as circMBOAT2 facilitates malignant biological behavior of PC through glutamine catabolism that is dependent on miR-433-3p/GOT1 axis (Zhou et al., 2021); CircFARP1 promotes GEM chemoresistance via cancer-associated fibroblasts associated with LIF/STAT3 axis in PC (Hu et al., 2022); CircCGNL1 suppresses PC progression via upregulating NUDT4/HDAC4/RUNX2/GAMT mediated apoptosis (Yuan et al., 2024). Here, HDAC4 is linked to pachyonychia congenita.