NGF and carcinoma: In line with this hypothesis, several articles have been published showing differences in the behaviour of different cell lines exposed to very low magnetic field intensities, for example, changes in neurite outgrowth in PC12 differentiated with NGF (Blackman et al., 1993a; Blackman et al., 1993b; Trillo et al., 1996; McFarlane et al., 2000), changes in gene expression in myeloid leukaemia cells (Tokalov and Gutzeit, 2004) or in anti-tumour behaviour in carcinoma cells (Novikov et al., 2009) with magnetic fields at very low intensities.