Dear Parvaiz Ahmad

I think lower the E value, the lower the probability of a random match and the higher the probability that the BLAST hit is related to the query. Along with E value, % identity with the maximum value defines ur result. All three complement ur result search and should be taken into consideration.

Regards

Ajaz

E-value probability takes into account the % identity and the % coverage. You can have 100% identity over a very short section of the protein and that will be a poor match.

Dear Parvaij, E-value,bit score and % Identity are important parameters to interpret BLAST result. But BLAST result interrupted by FP, FN,TP,TN possibilities, that's why such parameter becomes meaningless.