Despite the long-term evolution (LTE) signal, also known as fourth generation (4G) technology, is the most employed system for telecommunications and is widely deployed, only a few in vitro studies are related to exposure to LTE alone and in combination with other agents. To the best of our knowledge, the effect of simultaneous exposure to 4G LTE with other frequencies/signals has not been evaluated in any of these studies. In the present work, undertaken in the framework of the EU-funded NextGEM project, we investigated the non-thermal carcinogenic effect of LTE signal under a realistic scenario. Human neuroblastoma cells (SH-SY5Y) were exposed for three hours to 1950 MHz LTE signal, either alone or in combination with the chemical agent menadione (MD). Moreover, the effect of simultaneous exposure to 1950 MHz, 4G LTE signal and 2450 MHz Wireless-Fidelity (WiFi) signal was also evaluated to account for any possible effect due to the co-existence of these frequencies/signals in a realistic radio frequency exposure scenario. A waveguide-based exposure system, well characterized from dosimetric and experimental point of view, was used, and two SAR levels were tested in all cases. Cancer-related endpoints such as reactive oxygen species formation, apoptosis, and cell cycle progression were assessed in flow cytometry assays. In our experimental conditions, neither LTE exposure alone nor multiple LTE and WiFi exposure or LTE and MD co-exposure influenced the investigated cellular parameters in SH-SY5Y cells.