CDK4 and plexiform neurofibroma: Other altered genes implicated in cell cycle regulation included CDKN2A/B (gene loss, n = 10, 9.3%; MPNST, STS NOS, FDCS, bone OS, neurofibroma), CDK4 (amplification, n = 3, 2.8%; LPS), RB1 (splice site, n = 1, 0.9%; SNV, n = 1, 0.9%; STS NOS and LPS, respectively), CCNE1 (amplification, n = 3, 2.8%; ARMS, STS NOS, and LMS), and MDM2 (amplification, n = 2, 1.9%; LPS).