According to this website http://www.huffingtonpost.ca/2014/09/04/joan-rivers-dead-81-surgery_n_5745042.html Joan Rivers had a tattoo put on her arm in 2014, which said 6M in honor of the 6 Million Jews who were killed in the Holocaust.
This quote is from the website:
Earlier in 2014, she got inked: a half-inch-tall tattoo, “6M,” on the inside of her arm representing 6 million Jews killed in the Nazi Holocaust.
I was a big fan of Joan Rivers, starting back in the 1960s when she was on TV cracking jokes. I remember one joke about a young girl with big boobs: “She could not see her coloring box.”
I read one of her books about 20 years ago. She told about her early days, when she had a hard time establishing her career as a comedienne, but she never gave up.