The premessenger has 10 exons and covers 14.59 kb on the genome.

The complete mRNA is 3784 bp long. 2 alternatively spliced transcript variants encoding different isoforms have been found, but it has also been reported that transcription produces 16 different mRNAs, 15 alternatively spliced variants and 1 unspliced form. Of the 2 described variants, variant 1 (2,805 bp linear mRNA) contains a different 5 region, which includes a part of the coding sequence when compared to variant 2. Variant 2 (3,263 bp linear mRNA) contains an alternate 5 region, which includes an additional in-frame translation start codon, as compared to variant 1. It thus encodes a protein that is 39 aa longer at the N-terminus.

No pseudogenes have been found.

The hematopoietic protein tyrosine phosphatase (HePTP) protein is a 40,5 kDa protein of 360 amino acids. It is a class I non-receptor PTP that is strongly expressed in T cells. It is composed of a C-terminal classical PTP domain (residues 44-339) and a short N-terminal extension (residues 1-43) that functions to direct HePTP to its physiological substrates.

Thymus, spleen, leukocytes.

Cytoplasmic.

Protein tyrosine phosphatase activity, hydrolase activity, phosphoric monoester hydrolase activity, receptor activity- participation in MAPK signaling pathways, T cell receptor signaling pathway and protein amino acid dephosphorylation.
The protein can interact with tyrosine-phosphorylated MAPK1, MAPK3 and several other MAP kinases and suppress the MAP kinase activities. Plays a role in the regulation of T and B-lymphocyte development and signal transduction.

HePTP has high homologies with striatal-enriched phosphatase (STEP) and PCPTP (PC12 protein Tyr phosphatase).

No germline mutations are described.

Mutations have not been observed.