# CTX-001 — The International Collaborative Animal Study of mobile phone radiofrequency radiation carcinogenicity and genotoxicity: the Japanese study Why this matters This Japanese follow-up did not find significant increases in the brain and heart tumours being investigated. That limits the consistency of the cancer evidence. Survival differed between exposed and comparison animals, and an equipment failure altered part of the exposure; those details matter when comparing the studies. Id: CTX-001 Author: Katsumi Imaida Full Authors: Katsumi Imaida; Mayumi Kawabe; Jianqing Wang; Masanao Yokohira; Norio Imai; Kang-Hyun Han; Yong-Bum Kim; Sang Bong Jeon; Hye Sun Kim; Young Hwan Ahn Year: 2026 Title: The International Collaborative Animal Study of mobile phone radiofrequency radiation carcinogenicity and genotoxicity: the Japanese study Journal: Toxicological Sciences Citation: Imaida K, Kawabe M, Wang J, Yokohira M, Imai N, Han KH, Kim YB, Jeon SB, Kim HS, Ahn YH. The International Collaborative Animal Study of mobile phone radiofrequency radiation carcinogenicity and genotoxicity: the Japanese study. Toxicological Sciences. 2026;209(3):kfag002. doi:10.1093/toxsci/kfag002. Doi: 10.1093/toxsci/kfag002 Pmid: 41527296 Topic: Replication and cohort context Verification Group: Replication and cohort context Record Role: Replication or cohort context Featured: False Exposure: 900 MHz CDMA, target whole-body SAR 4 W/kg in reverberation chambers; daily 18 h20 with 10-min on/off cycles (about 9 h10 RF-on), from maternal gestational day 5 through lactation to postnatal day 21 and then 104 weeks after weaning. Approximately four weeks ran at about 2 W/kg because one amplifier failed. Design: 70 male Hsd:Sprague Dawley SD offspring/group selected at postnatal day 21 from three maternal groups (30 pregnant females/group): RF, chamber sham and cage control. RF pathology denominator 68 after two equipment-malfunction deaths were excluded. Finding: Male-rat follow-up at 4 W/kg, 900 MHz CDMA did not reproduce significant glioma/cardiac-schwannoma increases. Heart schwannoma: one in each cage/sham/RF group. Survival at 105 weeks: cage 34.3% (24/70), sham 42.9% (30/70), RF 64.7% (44/68); two equipment-malfunction deaths excluded. Retain sham comparison. Boundary: Specific replication context for RF-001. Lower sham than exposed survival, the amplifier interruption and denominator exclusions require attention. This protocol does not reproduce the Ramazzini lifetime far-field experiment. The Japanese survival issue cannot be generalised to the separate Korean arm. Protection Question: What explains the different tumour findings across protocols? Japanese survival and equipment issues matter, but cannot explain the separate Korean result or substitute for comparison with the Ramazzini exposure arrangement. Access: Primary full-text results/survival and publisher/PubMed records reviewed; not a complete supplement audit. Locator: Original accepted manuscript Materials and Methods pp.6-7 (exposure/amplifier); 2-Year Carcinogenicity Study p.12; Figure 2; Results survival p.18. Final Table 2 confirms group denominators 70/70/68. Notice: No editorial notice located in DOI/title checks on 2026-10-20; publisher notice-history audit not exhaustive. Funding: Japan Ministry of Internal Affairs and Communications grant 0155-0094, with Korean-government MSIT/IITP grants RS-2024-00466966 and 2019-0-00102; authors declare no conflicts. Funding text checked in accessible original accepted-manuscript PDF, p 31; final funding-page recheck not completed. Conflicts: Authors declare no conflicts or competing interests, as documented in the retrieved source disclosure. Source Url: https://pmc.ncbi.nlm.nih.gov/articles/PMC13078595/ Retrieval Links: https://pmc.ncbi.nlm.nih.gov/articles/PMC13078595/ | https://doi.org/10.1093/toxsci/kfag002 | https://academic.oup.com/toxsci/article/209/3/kfag002/8423504 | https://pubmed.ncbi.nlm.nih.gov/41527296/ Verification Date: 2026-10-20