Even when biologically speaking humans can live forever, there are still accidents, violence, natural disasters, etc, that can extinguish life.
Each threat is major topic in its own right but its important to keep an eye on them as the bigger the problem the longer it takes to fix it.
Artificial Intelligence (AI) - Will it help or destroy us?
Climate Change - technology should come up with solutions but I suggest erring on the side of caution for now
Energy - where is it all going to come from to power technological advances and maybe reverse climate change?
Earth Monitoring - massive monitoring projects to help predict and prevent natural disasters
Natural Disasters - earthquakes, volcanoes, tsunami and more
Pandemics - diseases can spread faster than we can produce cures and vaccines
Society - If society doesn’t survive, then you don’t survive… technology giveth, and technology taketh away!
Immortality roadmap - Turchin Alexei's maps of global catastrophic risks including natural disasters, biological weapons and genetic engineering.
Do you want to give birth in space? Apply here!Geek.com - 14-Jan-2019
Nice idea, but timelines are totally unrealistic, let alone the practicalities
Human cartilage tissue 3D bioprinted on ISSMed-Tech Innovation News - 10-Jan-2019
One small step for man, one bioprinted leg for mankind?!
Llama blood clue to beating all fluBBC - 02-Nov-2018
Llama antibodies able to attack parts of flu virus that don't mutate