World Health Organization (WHO) Status: In 2011, the WHO's International Agency for Research on Cancer (IARC) classified mobile phone RF radiation as "Group 2B". This means that it is said to be a "possibly carcinogenic to humans" factor, meaning that further studies are needed. Meanwhile, WHO scientists have found in their research that the risk of cancers such as glioma and salivary gland tumors has not increased despite years of mobile phone use. Ken Karibidis said about this research, "We have found no link between mobile phones and brain cancer or other head and neck cancers. No matter how much mobile phone usage has increased." said.