APPRIS P1: Transcript(s) expected to code for the main functional isoform based solely on the core modules in the APPRIS.

APPRIS is a system to annotate alternatively spliced transcripts based on a range of computational methods to identify the most functionally important transcript(s) of a gene.

TSL 2: A transcript where the best supporting mRNA is flagged as suspect or the support is from multiple ESTs

The Transcript Support Level (TSL) is a method to highlight the well-supported and poorly-supported transcript models for users, based on the type and quality of the alignments used to annotate the transcript.