Why is Misha meeting Uri important in the story?

Uri is the young boy Misha first meets and who changes Misha's life. He introduces Misha to a group of boys whom he lives with until they are separated. When the ghettos are built, Uri is able to work in the laundry in a hotel outside of the ghetto because of his non-Jewish looks. Uri helps Misha and guides him through lots of situations, advising him to do the right, and reprimanding him when he does the wrong thing. Misha learned from Uri a lot of things. In fact, Uri saves Misha's life when he shoots Misha and makes him lose consciousness before he rides the train.