LOINCActiveObservation

LOINC Code 21166-4: CD56 cells/Cells (Specimen)

21166-4 is a LOINC code used to identify CD56 cells/Cells (Specimen) in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Cells.CD56/Cells. It is commonly used with the system or sample type XXX.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Cells.CD56/Cells. It is commonly used with the system or sample type XXX.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Observation

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • CD56 cells/cells in Specimen
  • Cells.CD56/Cells
  • CD56 Cells; Cell; CELL MARKERS; Cellularity; Leu19; Leu-19; Misc; Miscellaneous; NCAM; Neural cell adhesion molecule; NKH1; Number fraction; Other; Percent; Point in time; QNT; Quan; Quant; Quantitative; Random; Spec; To be specified in another part of the message; Unspecified

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

CD56 cells/Cells (Specimen)CD56 cells/cells in SpecimenCD56 Cells NFr SpecCells.CD56/CellsCELLMARKCD56 cells/cells, SpecimenNFr

Frequently asked questions

Code details

Code21166-4
SystemLOINC
Display nameCD56 cells/Cells (Specimen)
DescriptionCells.CD56/Cells
Short nameCD56 Cells NFr Spec
ComponentCells.CD56/Cells
PropertyNFr
TimingPt
System (specimen)XXX
ScaleQn
ClassCELLMARK
Example units%
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0m
Last changed2.79

Consumer names

CD56 cells/cells, Specimen

Part names

Cells.CD56/CellsNFrPtXXXQnNumber FractionPoint in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 21166-4 | HealthAssure