LOINCActiveBoth

LOINC Code 49556-4: p16INK4a Ag Immune stain Ql (Tiss)

49556-4 is a LOINC code used to identify p16INK4a Ag Immune stain Ql (Tiss) 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 p16INK4a Ag. It is commonly used with the system or sample type Tiss.

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 p16INK4a Ag. It is commonly used with the system or sample type Tiss.

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: Both
  • Method: Immune stain

What it does not mean

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

Key facts

  • p16INK4a Ag [Presence] in Tissue by Immune stain
  • p16INK4a Ag
  • Antigen; Antigens; IHC; Imm; Immunohistochemical stain; Immunostain; ImStn; Imun; Imune; Ordinal; PATHOLOGY; Point in time; PR; QL; Qual; Qualitative; Random; Screen; St; Stains; Stn; Tissue; Tissue, 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

p16INK4a Ag Immune stain Ql (Tiss)p16INK4a Ag [Presence] in Tissue by Immune stainp16INK4a Ag Tiss Ql ImStnp16INK4a AgPATHp16INK4a antigen, TissuePrThr

Frequently asked questions

Code details

Code49556-4
SystemLOINC
Display namep16INK4a Ag Immune stain Ql (Tiss)
Descriptionp16INK4a Ag
Short namep16INK4a Ag Tiss Ql ImStn
Componentp16INK4a Ag
PropertyPrThr
TimingPt
System (specimen)Tiss
ScaleOrd
MethodImmune stain
ClassPATH
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.22
Last changed2.73

Consumer names

p16INK4a antigen, Tissue

Part names

p16INK4a AgPrThrPtTissOrdImmune stainPresence or ThresholdPoint in time (spot)Tissue and Smears

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.