TY - RPRT TI - A cautionary note concerning the possibility that transforming growth factor-beta is a switch factor that acts on primary B cells to initiate IgA expression. AU - J J Cebra AU - A George AU - R L Kerlin PY - 1991 DO - 10.1007/bf02919731 UR - https://pubmed.ncbi.nlm.nih.gov/1955766/ ID - 1955766 ER -