Project description:190 proteins were identified from three samples. Among them41 proteins were detected in sample Layer 1 and/or Layer 2 but not in sample Layer 3, and one protein (SPCS2) was detected all three samples but its relative abundance is higher in Layer 1 than that in Layer 3. These 42 proteins can be considered as the most possible candidates proteins which are specifically present in the secretory granules prepared in this experiment.