CDK4 and neurofibromatosis type 1: To provide a resource for research, we developed short-term cNF Schwann cell cultures from NF1 patients, from which we subsequently established the first semi-immortalized cNF cell lines through transduction with wild-type human telomerase reverse transcriptase (hTERT) and murine cyclin-dependent kinase 4 (mCdk4) genes.