PTEN and Lhermitte-Duclos disease: For example, knockout of the mTOR negative regulator PTEN results in increased neuro-axonal size in mice (Backman et al., 2001, Fricano et al., 2014, van Diepen et al., 2009) and in humans (Kwon et al., 2001, Marsh et al., 1999) with Lhermitte-Duclos disease.