To assess changes in neoplastic cell state and the tumor microenvironment with age and gain insights into the age-dependent effect of PTEN, we performed single-cell RNA sequencing (scRNA-seq) on cells from the tumor-bearing lungs of young and aged KT;H11LSL-Cas9 mice with tumors initiated with Lenti-sgInert/Cre (sgInert) and Lenti-sgPten/Cre (sgPten) (n = 4 mice per age-genotype group; Fig. 4a and Extended Data Fig. 5a,b). This evidence concerns the gene PTEN and neoplasm.