Who is CR in the nonfiction book, This Is Going to Hurt?

CR is a patient that was diagnosed with cancer, who Kay is extremely fond of. He spent hours talking to her about her life and running through the "what ifs" of her life. He realizes that he is the "only one she's been totally honest with" and tells that reader that it is a "strange privilege, an hour" (59). Kay realizes during this interaction the impact that his patients have on him and calls his mom as a result of his relationship with CR.