Recent analyses revealed that, similar to de novo SCLC, XPO1 mRNA levels increased in pre-transformed NSCLC clinical specimens from patients carrying concomitant TP53 and RB1 inactivation, with double TP53/RB1-mutated samples showing the highest XPO1 expression relative to their double wild-type counterparts. The gene discussed is RB1; the disease is small cell lung carcinoma.