The original TE671 cell line was initiated by explant culture from biopsy fragments of a cerebellar medulloblastoma. The cell strain was isolated by picking a few of the multilayered round or polygonal cells which were interspersed in monolayers of stromal glial cells using Pasteur pipettes. Forms colonies in soft agar medium. Neural or glial elements were not observed upon examination with the electron microscope and no viruses were detected. The cells possess functional nicotinic acetylcholine receptors. No choline acetyltransferase or tyrosine hydroxylase activities are detectable. Cytogenetic studies by Stratton et al. (1989) have revealed that TE671 and RD are derivatives of the same cell line of rhabdomyosarcoma origin.