Thus, to perceive how skin allergen exposure modulates the basal levels of Hmox1 gene in neuronal cells, the N2a-wt and N2a-APPwt cells were incubated in the absence or in the presence of skin allergens, for 3 and 6 h, and the mRNA levels were analyzed by real-time RT-PCR (Figure 5). The gene discussed is HMOX1; the disease is neoplasm.