NFKB1 and Cowden syndrome 1: While most CS affected individuals are known for their photosensitivity, previous work has shown that nicotinamide supplementation improved cell viability loss and attenuated the inflammatory response in photosensitive skin [16] especially through reducing expression level of NF-κB subunit (p50) [68], which was the case of P50 expression level, noted in CS fibroblasts.