Although E50K and M98K mutants of OPTN when expressed in 661W (this study) and RGC-5 cells31,39 induce more cell death than wild type OPTN, some other glaucoma-associated mutants (H26D, H486R, T202R, E322K) did not induce this cell death in 661W (this study) as well as RGC-5 cells31,39. This evidence concerns the gene OPTN and glaucoma.