[1] Following injury, neoblasts rapidly divide and generate new cells, which allows planarians to regenerate any missing tissue.

[5] The initial wound response is characterized by an increase in the number of cell divisions and by expression of injury-response genes.

[8][9] Inhibition of smedwi-2 or smedwi-3 gene expression blocks regeneration, impairs tissue maintenance and leads to death.

Sigma neoblasts produce brain, intestine, muscle, excretory, pharynx, and eye cell types.

Analysis of the gene Smed-betacatenin-1, encoding a Wnt pathway effector, has revealed its role in regulating the anterior-posterior axis.

[11] Alejandro Sanchez-Alvarado and Philip Newmark transformed planarians into a model genetic organism in the beginning of the 20th century to study the molecular mechanisms underlying regeneration.

Schmidtea mediterranea has emerged as the species of choice for research due to its diploid chromosomes and the existence of both asexual and sexual strains.

[14] Recent genetic screens utilizing double-stranded RNA technology have uncovered 240 genes that affect regeneration in S. mediterranea.

Planarians can regenerate any body part from small pieces in a few days and have many adult stem cells.