Additional Study Information: The purpose of this study is to find out if the experimental product, axicabtagene ciloleucel, in combination with either rituximab or lenalidomide is safe and effective in treating lymphoma. Kite Pharma, Inc., (Kite) is the sponsor of this study. The sponsor is funding this research study and has also designed the trial. The sponsor is testing an experimental treatment named axicabtagene ciloleucel in combination with either rituximab or lenalidomide. "Experimental" means that the drug combination in this study has not been approved for marketing by the United States Food and Drug Administration (FDA) in the USA or health regulatory authorities in other countries. All study participants will receive either axicabtagene ciloleucel and rituximab or axicabtagene ciloleucel and lenalidomide.