TSPAN6 and familial pancreatic carcinoma: Next, to determine the role of elevated expression of TSPAN6 in suppressing RAS-mutant human cancers in vivo, we used a doxycyclin (Dox)-inducible Tet ON/OFF switch to regulate TSPAN6 expression in two human K-RAS activating mutant pancreatic cancer cell lines, MIA PaCa2 and PANC1 (Fig. 3a and Supplementary Fig. 2a).