NABP2 and neoplasm: However, during this period, 11 out of 35 (31.4%) Rosa26-CreERT2: Ssb1−/− mice developed tumours, in contrast to only 2 out of the 35 (5.7%) Ssb1+/− mice, revealing a statistically significant difference (**P<0.01) in tumour-free Kaplan-Meier survival analysis (Figure 8A).