POLG and cancer: Examination of components comprising polymerases POLA, POLB, POLD, POLE, POLG, POLH, POLI, POLK, POLL, POLM, POLN, and POLQ showed POLE (catalytic subunit) expression elevated significantly in subtype 2 (Table 4); accessory subunits (POLA2, POLD2, and POLE2) were significantly elevated in subtypes 2 and 3, potentially signifying a function other than structural for their respective polymerase complexes in cancer (Table 5).