FPKMFPKM

FPKMFPKM is not a standard or widely recognized term in genomics. In most published contexts, the acronym FPKM refers to Fragments Per Kilobase of transcript per Million mapped reads, a normalization metric used in RNA sequencing to quantify gene expression. The repetition in the string “FPKMFPKM” is likely the result of a typographical duplication or a dataset-specific label rather than a distinct measurement.

In RNA-Seq analysis, FPKM is calculated by counting fragments mapped to a gene, dividing by the gene length in kilobases, and dividing by the total number of mapped reads in millions. This yields gene expression values that can be compared across genes within a sample and across samples, though with caveats.

If a source uses the exact term “FPKMFPKM,” it should define what is meant. Possible interpretations include two separate FPKM values reported for two samples or conditions (e.g., an A vs B comparison), a concatenated representation in a table, or a typographical duplication. Absent explicit definition, the term is ambiguous and should not be treated as a distinct metric.

Limitations of FPKM include sensitivity to gene length and sequencing depth, issues with comparing samples of different composition, and problems with low-count genes. TPM (Transcripts Per Million) is sometimes preferred for within-sample comparisons, and more robust cross-sample analyses often rely on count-based methods with proper normalization.

Readers encountering FPKMFPKM should consult the original article or data repository for explicit definitions. If you have a particular study or dataset where this term appears, providing context can help determine its intended meaning.