PTEN deficiency enhances MC degranulation and cytokine production via FcϵRI or in combination with Kit. (A) FcϵRI-mediated MC degranulation as measured by β-hexosaminidase release. SCF (10 ng/mL) was used in combination with IgE/Ag. The percentage of β-hexosaminidase released after stimulation is expressed as a percentage of total cellular β-hexosaminidase. (Inset) β-hexosaminidase release with SCF stimulation in the absence of IgE/Ag. One representative of 3 experiments is shown. (B-D) IL-3, IL-6, and TNF production was measured by ELISA. (Inset) Cytokine release with SCF stimulation in the absence of IgE/Ag. Statistical analysis by an unpaired 2-tailed Student t test compared with control cells stimulated with SCF: *P < .05; **P < .01; ***P < .001. One representative of 4 experiments is shown.