Ptprb, also known as protein tyrosine phosphatase receptor type B or vascular endothelial protein tyrosine phosphatase (VE-PTP), is a transmembrane protein tyrosine phosphatase. It is involved in multiple biological processes, acting as a negative regulator of vascular growth factor tyrosine kinases [3]. It is also associated with pathways such as the angiopoietin-Tie2 signaling pathway [6]. Ptprb is important in angiogenesis, blood vessel remodelling, and branching morphogenesis [3,5]. Genetic models, like KO/CKO mouse models, can be valuable for studying its functions.

In the context of diseases, in pulmonary fibrosis, the expression level of PTPRB is reduced in both patients and mouse models. Forsythoside A can ameliorate pulmonary fibrosis by inhibiting lung fibroblast proliferation and endothelial-to-mesenchymal transition, and this effect may be related to PTPRB [1]. In colorectal carcinoma, PTPRB promotes metastasis via inducing epithelial-mesenchymal transition. Knockdown of PTPRB decreased the invasive ability of CRC cells in vitro and tumor metastasis in vivo [2]. In angiosarcoma, PTPRB harbored predominantly truncating mutations in some tumors, highlighting its potential role in this malignancy [3]. A rare homozygous variant in PTPRB was associated with human hypoplastic left heart syndrome, and in silico and splicing assays indicated potential pathogenic mechanisms [4]. In NSCLC, overexpression of PTPRB reduced cell proliferation, colony formation, soft agar growth, and cell invasion, while knockdown increased Src phosphorylation and cell invasion [7]. In brown adipocyte differentiation, PTPRB functions as a negative regulator by suppressing the tyrosine phosphorylation of VEGFR2 [8].

In conclusion, Ptprb is a crucial regulator in various biological processes. Studies using KO/CKO mouse models and other loss-of-function experiments have revealed its significance in diseases such as pulmonary fibrosis, colorectal carcinoma, angiosarcoma, hypoplastic left heart syndrome, NSCLC, and in the regulation of brown adipocyte differentiation. Understanding Ptprb's functions provides insights into disease mechanisms and potential therapeutic targets.