Hi, my father has (had?) type 4 thyroid cancer and talks about calcitonin count. He had surgery and I believe this brought the count down significantly. He said the count has an is going up - which is normal apparently - but more recently the pace of the increase is rising. I want to understand the different levels of 'risk'. That is, how high is the number when still considered 'green', how high for yellow, amber, red, deep red.