Leprosy

Level 4 Cleric failed his initial save and has been infected by the disease leprosy.
Created was level 1. Cleric is Level 4. What must the Cleric roll to sure disease
And abolish this infliction? DC 25?

Correction--
Make that DC 20? For leprosy?
Inflicting creature is CR1...

What is the save for the level 4 Cleric with cure disease?
How does this work? What's the D.C. Number?

The Fort DC of Leprosy is 20. As per Remove Disease, this is also the DC of the caster level check to remove it.

There is no change in the DC based on the level or CR of the inflicting creature. Only some abilities or class features can alter the DC needed, and typically not in the infected's favor.