Scientific ethics is a relatively new issue in China. In the past, most Chinese researchers were merely following in the footsteps of their contemporaries overseas, but now they have caught up and, facing the frontier of the unknown, must make their own judgements on thorny ethical issues that are often further complicated by cultural, religious or commercial conflicts. Listed below are some of the spikiest topics currently being discussed in research communities throughout mainland China. Individual teams are not singled out because the government has funded more than one institution for each of these areas, and many of the scientists involved would only speak on condition of anonymity. Creating new viruses Many laboratories in mainland China are using cutting edge technology to develop viral strains that do not exist in nature. These manmade mutants, hybrids or crossbreeds can help scientists to better understand the evolution of certain viruses and their deadliness. Consequences if such infectious agents made it out of the lab however could potentially be severe. Human embryo modification Embryonic stem cells may contain the secret for the cure of many human ailments ranging from organ damage to cancer, but there is no clear consensus in the Chinese scientific community over where an embryo should be regarded as human, or just a dispensable experiment subject like a mouse. In April 2015, researchers in Guangzhou announced that they had successfully modified a human embryo for the first time. Screening for genetic traits Several research teams have been collecting genetic samples in high schools, juvenile detention centres and prisons to find out whether certain genes could lead to violent or other negative traits. Critics of such practice have warned that the findings of these studies could be biased, and the data may be abused by the authorities to label a person based on the circumstances of her birth. Cryogenic freezing If a human body could be stored at extremely low temperatures without taking physical damage, there is a chance that the person could be revived far into the future and even retain his or her memory. Several research teams engaging in cryonics have received ample funding from both the government and the private sector in recent years, but critics have said the thinking behind the projects is dubious at best because current technology lacks the ability to bring even a deep-frozen rat back to life. Tracing plant micro-RNA It has been long believed that plants' genetic molecules – such as RNA and DNA – do not mingle with those of humans. This formed one of the core arguments for the safety of genetically modified food such as rice or corn, but some Chinese researchers claim to have found within plants an elusive molecule called micro-RNA which could directly bind with human cells and change their function. These claims have prompted huge controversy in research communities around the world and some critics said they were unable to repeat the Chinese team's observations in their own labs. If the claims by Chinese scientists are true, the safety of all GM foods on the market today would have to be reexamined.