Venn diagrams of differentially altered genes/probes in response to HAL-PDT. A, includes up-regulated and down-regulated; B, only up-regulated; C, only down-regulated genes/probes at 1, 2 and 4 h time course. Each circle represents one time point as indicated. A total number of differentially expressed genes in the group are given in the parentheses. The intersections indicate numbers of genes/probe that are shared between the different time points, i.e. the genes that were steady induced. The number in the right bottom of each square indicates a total post processed and analyzed number of genes/probes minus the number of differentially expressed genes presented in circles.