This is the 3126th most frequent Turkish word.
den
"Den" in Turkish means "from" or "than" (used as a suffix with nouns).
The word 'den' here is used as an ablative suffix attached to 'ev', meaning 'from (the) house'.
Evden aceleyle çıktı.
He left the house in a hurry.
The word 'den' here forms a possessive structure to indicate 'one of' when followed by a possessive suffix.
O sorunlarımdan biridir.
It is one of my problems.
The word 'den' functions as an ablative suffix, connecting 'sen' (you) to indicate a source.