POLA2 and lung cancer: Cir_POLA2 has been reported as an oncogene of lung cancer.19 It has been found that overexpression of Cir_POLA2 can promote the proliferation of acute myeloid leukemia cells.20 Circ_POLA2 may upregulate the G protein subunit beta 1 (Notch pathway-related molecules) by serving as an endogenous competing RNA for miR-326.14.21 Guanine nucleotide regulatory protein (G protein) is the core of normal liver cell function and is related to the occurrence and progression of liver disease.