The Gamma Gap is the difference between total serum protein and albumin. It is frequently used clinical screening measure for both latent infection, malignancy, Multiple Myeloma.
“The gamma gap is an independent risk factor for all-cause mortality at values as low as 3.1 g/dl (in contrast to the traditional definition of 4.0 g/dl), and is strongly associated with death from pulmonary causes. Future studies should examine the biologic pathways underlying these associations.”
Further Reading
Juraschek SP, Moliterno AR, Checkley W, Miller ER. The Gamma Gap and All-Cause Mortality. Lazzeri C, ed. PLoS ONE. 2015;10(12):e0143494. doi:10.1371/journal.pone.0143494.
http://www.bloodjournal.org/content/130/Suppl_1/4407?sso-checked=true