AKT1 and cutaneous melanoma: Loss of PTEN is detected in up to 20% of cutaneous melanomas, most commonly in tumors with a concurrent BRAFV600 mutation, thus resulting in concurrent activation of the RAS-RAF-MEK-ERK and PI3K-AKT signaling pathways.14 In addition to mutations in pathway components, the PI3K-AKT pathway can also be activated by alterations in growth factor receptors, particularly RTKs.