Effects of various substitutions at residue 232 of perforin on RBL-mediated cytotoxicity.⁵¹Cr-release cytotoxicity assays using transfected RBL cells and Jurkat target cells at the E/T ratios indicated, comparing the cytotoxic function of R232C and R232H (substitutions identified in HLH patients) with WT and R232S (flounder) perforins. Data shown are means ± SD.