Studying Lineage Plasticity One Cell at a Time.

The development and consequences of lineage plasticity during tumorigenesis have remained mysterious due to the limits of single-cell analysis. In this issue of Cancer Cell, LaFave et al. and Marjanovic et al. identify highly plastic subpopulations within lung adenocarcinoma that may underlie intratumoral lineage heterogeneity, metastasis, and acquired resistance to chemotherapy.