PDE6D and cancer: By contrast, Deltaflexin3 displayed the overallhighest selectivityfor PDE6D-dependent and KRAS mutant,as compared to HRAS mutant cancer cell lines (Figure 4B; Figure S3D), consistent with its K-RasG12V selectivity detectedby BRET (Figure 2B)and its off-target activity being lowest among the investigated compounds(Figure 3A and 3C).