“Do you know”—he repeated more slowly—“what the five types of brothers are?” “You mean, like brother-in-law?” “Real brother. Wife’s brother. Sister’s husband. Wife’s sister’s husband.” I counted in my head. “That’s four.” “So what’s the fifth?” he asked. “No idea.” “Brother from another mother. That’s what we are now, Mitch.
6. Brothers in arms
7. Brothers in Christ
Technically, his fifth "brother" could be brothers in adversity (or the opposite comfort or peace).
