check to make sure if the cell is correct/right/ready to move on to the next stage.
oncogenes
proto-oncogenes
checkpoint
Checkpoint is a noun.
he reached the checkpoint
there is no checkpoint
Checkpoint Charlie
Checkpoint Charlie
G1/S checkpoint
Futian Checkpoint Station was created in 2007.
Checkpoint Charlie Museum was created in 1962.
Woodlands Train Checkpoint was created in 1998.