test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node6
GO:0008150
biological_process
node2->node6
node3
BFO:0000001
entity
node3->node1
node4
GO:0012501
programmed cell death
node5
GO:0048102
autophagic cell death
node4->node5
node7
GO:0009987
cellular process
node6->node7
node8
GO:0008219
cell death
node7->node8
node8->node4