True about cardiolipin is all except
Found in inner mitochondrial membrane
Play role in process of apoptosis
Is Diphosphatidyl glycerol
Has choline base which has labile methyl group
Cardiolipin (diphosphatidylglycerol) is a phospholipid present in mitochondria.  
It is formed from phosphatidylglycerol, which in turn is synthesized from CDP-diacylglycerol and glycerol 3-phosphate.
Cardiolipin, found in the inner membrane of mitochondria, has a key role in mitochondrial structure and function and is also thought to be involved in programmed cell death (apoptosis).
Cephalin: Has choline base which has labile methyl group.
 
Harper's Illustrated Biochemistry 30th edition page no 248