Evidence map›Paper›PMID 42824757›Full record

ReviewResearch and practice in thrombosis and haemostasis2026

Extravascular factor IX: a semicentennial narrative review.

Tvisha Subhasish, Christopher R Reed

Abstract readReview
In one paragraph

Review in Research and practice in thrombosis and haemostasis, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors.

Tvisha SubhasishKansas City University College of Osteopathic Medicine, Kansas City, Missouri, USA.
Christopher R ReedDuke University School of Medicine, Durham, North Carolina, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Coagulation factor IX (FIX) is a serine protease that is crucial for normal hemostasis in vertebrates. Unlike other soluble vitamin K-dependent procoagulant enzymes, there is an "extravascular reservoir" of FIX in various tissues. The extravasation of FIX and its subsequent maintenance outside of circulation have long been attributed to its ability to bind collagen IV. This property is conferred by a short, specialized region of its phospholipid-binding gamma-carboxyglutamic acid (Gla) domain. Collagen IV is a nonfibrillar extracellular protein found primarily in basement membranes that assembles into sheet-like supportive structures around blood vessels and epithelia, providing a convenient scaffold for this "hemostatic barrier." Early seminal investigations from 1980 to 2000 suggested the existence of a large extravascular reservoir containing the majority of a vertebrate organism's FIX. The subsequent development of a FIX-deficient mouse model, identification of the amino acid residues responsible for FIX's collagen binding (K5 and V10), and development of enzyme mutants with high and low affinities for collagen IV afforded new insights into the hemostatic importance of this property from 2000 through 2020. Recent interest on the topic has been catalyzed by therapeutic implications for hemophilia treatment. For example, studies have examined the hemostatic and pharmacokinetic effects of enhanced collagen binding on the hyperactive FIX variant (Padua) currently in trials for hemophilia B gene therapy. In this review, we highlight research updates on extravascular FIX since 2020 and present remaining questions to help guide future investigations.

Indexed as

Factor IXHemophilia BAnimalsCollagen Type IVHemostasisHumansMiceProtein BindingCollagen Type IVFactor IXcollagenfactor IXhemophilia Bhemorrhagethrombosis

Identifiers

PMID42824757
PMCPMC13629327

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.