When somebody dies, which are the last surviving cells of his/her body? Those of hair, nails, or some other obscure but resilient cells?
Shedding light on why and how they are so vital might boost our knowledge of survival pathways.
They found live skeletal muscle stem cells in human corpses 17 days after death (LiveScience, 2012).
They isolated live stem cells from the bone marrow from human fingers 5 days after death and transformed them into cartilage, bone and fat cells (NewScientist, 2013).
The survived cells were in a dormant state with very little metabolic activity.
From what I have read, it looks like white blood cells have been found to survive the longest (up to 70 hours after death). This being said, I have also seen people who say that red blood cells would survive the longest because they do not need oxygen to survive (they have no mitochondria and thus do not do aerobic respiration). Since you seem to be interested in survival pathways, blood cells are probably not terribly useful. It seems that many transplantable organs like the kidneys can survive for up to an hour (provided that they are chilled to avoid cell death).