PKN3 and melanoma: PKN1 can also inhibit the Wnt/beta-catenin signaling, especially in melanoma cells.It was demonstrated that diminishing PKN1 expression induced apoptosis in melanoma cells.14 Different PKN isoforms perform different functions depending on the tissue type.23 For example, the PKN3 and PKN1 isoforms play a significant role in prostatecancer development, and the same is true for the PKN2 isoform in bladder cancer.