Rasgrp1^+/− promotes ERK hyperactivation and expansion of early T-cell precursors in Nras^Q61R/+ mice. (A) Experimental scheme. R+/− and R+/−; Q/+ mice were euthanized at about 6 months after pI-pC treatment along with age-matched control mice. (B) Quantification of Rasgrp1 and pERK levels in thymocytes. Rasgrp1 levels were quantified against the levels of Gapdh using ImageStudioLite software. pERK levels were quantified against total ERK levels. The values in control cells are arbitrarily set at 1. (C) Quantification of the number of Thy1.2⁺ Mac1⁺ thymocytes. (D) Quantification of the number of early T-cell precursors. DN, CD4⁻ CD8⁻ T cells; DN1, CD44⁺ CD25⁻ DN cells; DN2, CD44⁺ CD25⁺ DN cells. Data were plotted as mean + SD. P values were calculated with a 2-tailed Student t test. *P < .05; **P < .01.