Given the positive relationship between the clonal expansion power of Tsc1-deficient cells and MG degeneration in the Tsc1-cko mouse retinas, we hypothesized that the Tsc1-deficient RPCs in Tsc1fl/fl;Tyrp1-Cre mouse retinas were likely to be too old, in mitotic terms, to preserve the survival program intact in their descendent MG. Here, TSC1 is linked to myasthenia gravis.