NF1 and cancer: To evaluate the contribution of the Nf1+/− microenvironment to cancer progression in a mouse model that develops NF1-associated benign and malignant tumors, we analyzed a cohort of 216 PLPCreERT2; Nf1f/f (Nf1 knockout in Schwann cells, but wild type in all other tissues) and PLPCreERT2; Nf1f/− (Nf1 knockout in Schwann cells, but heterozygous in all other tissues) mice.