KRT5 and neoplasm: Despite strong expression of the oncogene, only about 50% (n = 22/43) of transgenic fish developed tumors in the head region at 1 year of age (Figure 2E, E’), making the overall tumor penetrance of transient Tg(gfap:Gal4VP16; UAS:mCherry-KRASG12V) transgenic fish similar to that of tumors from Tg(krt5:Gal4VP16; UAS:mCherry-KRASG12V) (Figure 2F).