DLC1 and Familial prostate cancer: While WT-DLC1 but not K714E-DLC1 reduced the levels of active RhoA-GTP in DU145 prostate cancer cells as shown previously (Supplementary Fig. 1b) [27, 28], the levels of RhoA-GTP and p-MLC2 remained unaltered in melanoma cells treated with either WT-DLC1 or K714E-DLC1 (Supplementary Fig. 2a, b).