TSC2 and Birt-Hogg-Dube syndrome: Interestingly, BHD is a member of the hamartoma syndrome family that includes Cowden syndrome (CD, affected gene PTEN), Peutz-Jeghers syndrome (PJS, affected gene LKB1), and tuberous sclerosis complex (affected genes TSC1/TSC2) [14], [15], [16].