RB1 and small cell lung carcinoma: To determine whether MYC expression is similarly increased in SCLC cell lines after platinum resistance is acquired two independent cell lines derived from a genetically engineered mouse model driven by the loss of Rb1 and Trp53 from lung neuroendocrine cells (RP mouse model) were repeatedly treated with an LD50 dose of carboplatin and cells considered resistant if an increase in LD50 of at least fivefold was achieved.