PIK3CA and adenocarcinoma: The study revealed that PIK3CA mutations were less frequent in GCA compared to typical adenocarcinoma.[70] Lu et al conducted genetic testing on 15 GCA patients and found that TP53 (53%), STK11 (33%), CDKN2A (27%), ARID1A (20%), and PTEN (20%) were the most commonly mutated genes.