Arising from C. H. Wan, X. Z. Zhang, X. L. Gao, J. M. Wang & X. Y. Tan 477, 304-307 (2011). Magnetoresistance exhibited by non-magnetic semiconductors has attracted much attention. In particular, Wan et al. reported room-temperature magnetoresistance in silicon to reach 10% at 0.07 T and 150,000% at 7 T-'an intrinsically spatial effect'. Their supply voltage was approximately 10 V (ref. 12), which is low and approaches the industrial requirement. However, we have found their large magnetoresistance values to be experimental artefacts caused by their method of measurement. The true room-temperature magnetoresistance of the devices described in ref. 12 is low with a magnetic field of up to 7 T and a supply voltage of around 10 V and hence these devices cannot offer large magnetoresistance with low supply voltage to industry. There is a Reply to this Brief Communication Arising by Zhang, X. Z., Wan, C. H., Gao, X. L., Wang, J. M. & Tan, X. Y. Nature 501, http://dx.doi.org/10.1038/nature12590 (2013).