PIK3CA and cervical cancer: In addition, DNA copy number losses in the chromosomal regions 2q, 4p, 4q,6p, 6q, 8q and 17p (TP53 region), and copy number gains in chromosome 1 are more common in HPV31-positive than in HPV16-positive cervical cancers, whereas DNA copy number gains in chromosome 3q (PIK3CA region) are more common in HPV16-positive than HPV31-positive cervical cancers [84].