ICD-10 code D70 for Neutropenia is a medical classification as listed by WHO under the range -Other disorders of blood and blood-forming organs .
Jesus included Peter in his inner circle when he took Peter, James, and John into the house of Jairus, where Jesus raised Jairus' daughter from the dead (Mark 5:35-43). Later, Peter was among those same disciples Jesus chose to witness the transfiguration (Matthew 17:1-9).
Mark was the writer of the gospel bearing his name but Peter is actually the one behind the gospel. It is only Mark who wrote down what Peter experienced during his time with Christ.