When it is used in relation to certain dorid nudibranchs such as Peltodoris nobilis, it means the nodules on the dorsum of the animal.
Kraus (1951) proposed that homozygosity of a gene is responsible for a pronounced tubercle, whereas the heterozygote shows slight grooves, pits, tubercles or bulge.
Scalene tubercle, a slight ridge on the first rib prolonged internally into a tubercle
In 1925, Treat Baldwin Johnson and Coghill were detected a minor amount of a methylated cytosine derivative as a product of hydrolysis of tuberculinic acid, from avian tubercle bacilli, with sulfuric acid.