test
node1
BFO:0000003
occurrent
node1->node1
node2
BFO:0000015
process
node1->node2
node7
GO:0008150
biological_process
node2->node7
node3
BFO:0000001
entity
node3->node1
node4
GO:0050896
response to stimulus
node5
GO:0009605
response to external
stimulus
node4->node5
node6
GO:0071496
cellular response to
external stimulus
node5->node6
node7->node4