The data set shows features for immunofluorescence signals which identify caspase-2 and p53 in HeLa cells cultured in the presence of 1 mM and 20 mM sodium valproate (VPA) for 4 h, and 20 mM VPA for 48 h. These proteins are ascribed to be potentially associated with the incidence of mitotic catastrophe, an oncosupressive event. Cells were fixed in methanol at -20 °C for 10 min, rinsed in PBS, permeabilized with 0.2% Triton X-100 for 10 min, and blocked in 5% BSA for 1 h. Rabbit anti-caspase-2 and anti-p53 were used as primary antibodies (1:200 and 1:100 dilutions, respectively). Goat anti-rabbit conjugated with Alexa-Fluor 488 (1:500 dilution) was used as secondary antibody. The images were captured in a Leica TCS SP5 II confocal microscope at the Laboratório Central de Tecnologias de Alto Desempenho em Ciências da Vida (LaCTAD/UNICAMP). The evaluated features were: total fluorescence area, mean gray value (average pixel intensity within a region of interest), standard deviation, minimum and maximal intensity (lowest and highest pixel intensity value within a region, respectively), integrated density (backgound-normalized sum of the pixel intensity values within the image or selection), and raw integrated density (sum of the values of the image pixels).