From the chylous effusion of a patient affected by LAM associated with TSC, we isolated a homogenous population (LAM/TSC cells) positive to α-actin antibody, marker of smooth muscle cells, hamartin, and the specific markers for TSC and LAM cells, HMB45 and CD44v6 antibodies (Fig. 1A). This evidence concerns the gene TSC1 and tuberous sclerosis.