Author: Nat Pernick, M.D. (see Authors page)

Revised: 16 October 2015, last major update January 2014

Copyright: (c) 2003-2015,, Inc.

PubMed Search: ALK[title], ALK1[title]
Cite this page: ALK. website. Accessed April 24th, 2017.
Definition / General
  • See also NPM-ALK fusion protein
  • Anaplastic lymphoma kinase gene is at 2p23; protein is called ALK1, CD246
  • Membrane spanning tyrosine kinase receptor, member of insulin receptor family
  • Is NOT the same as Ki-1/CD30, contrary to some references
  • Interpretation: usually cytoplasmic and nuclear staining
  • References: OMIM #105590
Diagrams / Tables

ALK signaling

Pathways in ALK+ anaplastic large cell lymphoma

Clinical Features
Micro Images

Images hosted on other servers:

Anaplastic lymphoma

Anaplastic lymphoma: various images

Diffuse large B cell lymphoma (fig B)

Inflammatory myofibroblastic tumor (IMT) of bladder

IMT of abdomen

IMT of larynx
(fig 2C)


Inflammatory breast carcinoma is ALK-


Renal cell carcinoma with ALK gene rearrangement

Images hosted on

Alveolar rhabdomyosarcoma

Anaplastic lymphoma

Inflammatory myofibroblastic tumor (IMT) of bladder

IMT-site unspecified

Positive Staining - Normal
  • Embryonic neurons of central and peripheral nervous systems, weakly positive in adult brain
  • Normal small intestine, T cells
  • Weakly positive in colon, prostate
Positive staining - Tumors
Negative Staining
  • Fibromatosis, GIST, nodular fasciitis and normal lymphoid tissue
Molecular / Cytogenetics Images

FISH: ALK+ large cell lymphoma