A clear distinction between individuals with TSC gene mutations who acquire Tuberous Sclerosis vs. S-LAM is that the somatic mutations in TSC1 or TSC2 are more widespread in those with TSC, and are typically also present in the germline (Dabora et al., 2001; Strizheva et al., 2001). Here, TSC1 is linked to lymphangioleiomyomatosis.