How does Miss Peregrine's Home for Peculiar Children by Ransom Riggs relate to the Holocaust?

The novel alternates between realistic and fantasy worlds in conveying the way that Jacob learns about the Second World War, when the Nazis killed and persecuted millions of Jews, along with gay people, Romanis, and others. Jacob’s Grandpa Portman is a Holocaust survivor. As a child, he had lived in Poland but was evacuated to Wales. During the war, many children were sent away from their homes on the Continent to England and other countries, and many English children were sent away from the urban centers to the countryside.
In the novel, the Holocaust is personified as a group of monsters called the Hollowgast. Much of the novel involves Jacob’s deciphering which aspects of his grandfather’s statements and memories are based in fact and which are products of his imagination. For example, Grandpa tells Jacob to go to the home in Wales and find the hawk; it turns out that the administrator was named Miss Peregrine, which is a type of falcon, a bird closely related to the hawk. He was also fearful that the monsters would return, and Jacob starts to see them in his dreams. When Jacob finally gets to the school, he realizes that some of Grandpa’s apparent imaginings are true: Miss Peregrine can turn into a bird, the Hollowgast monsters have embodied forms, and Jacob can travel back in time to the 1940s. These kinds of physical manifestations become real because this is a fantasy novel, but the kinds of danger that Jacob faces are those that actually occurred during the war.

Two ways that Miss Peregrine's Home for Peculiar Children can relate to the Holocaust is in its treatment of persecution and its display of people who feel compelled to take action in the face of injustice.
The persecution of the peculiars is one way the novel connects to the Holocaust.  The syndrigast, or people who are "peculiar," are viewed with hostility.  They are not like everyone else.  Their difference is what causes others to hunt them down and kill them.  This is similar to the way that Nazis saw Jewish people.  They sought to capture and kill them.  The peculiars must flee to different areas to avoid capture, a sad parallel to what Jewish people had to do during the Holocaust.  
Another connection to the Holocaust is how the novel shows responses to human suffering.  Both Jacob and his grandfather make conscious choices to fight for people who are suffering.  Jacob's grandfather committed himself against the Nazis and to fighting monsters.  For his part, Jacob resolves to help the peculiars.  In both settings, people are taking action against injustice.  Jacob and his grandfather could have chosen to do nothing.  Yet, they feel compelled to act. This shows a clear connection to the Holocaust time period.  Even though the Nazis killed many people, there were some who stood up for the rights of others. For example, Johanna Eck was a German who hid Jewish people in her home.  Suzanne Spaak left her life of wealth and privilege to join the Underground.  Like Jacob and his grandfather, they undertook great risk to do what they felt was right.