CA4 and glioblastoma: Antiproliferative activities against cell lines A-549 (human lung carcinoma cell line), MCF-7 (human breast adenocarcinoma cell line), SKBR3 (human breast adenocarcinoma cell line), HT-29 (human colorectal adenocarcinoma cell line), SF188 (paediatric glioblastoma cell line), GBM10 (human glioblastoma cell line), T98G (human glioblastoma cell line) were appraised for all of the conjugates of CA-4 with piperlongumine derivatives.