RB1 and small cell lung carcinoma: Accordingly, deletion of Rb1 and Trp53 along with Pten and Rbl1 (p107) with Ad5-K5-Cre, which targets cells similar to K14-expressing cells, also led to the development of SCLC, supporting the idea that basal cells can serve as a cell of origin for SCLC in the context of a different set of driver lesions (Lázaro et al. 2019).