ERBB2 and neoplasm: Rosa-Rosa and coworkers reported the molecular analysis of 39 tumor samples of PILC showing that: all cases showed the absence or aberrant expression of E-Cadherin and abnormal expression of β-catenin and p120; CDH1 (89%), PIK3CA (33%), and HER2 (26%) were the most recurrently mutated genes; a higher frequency of mutations in ARID1B, KMT2C, MAP3K1, TP53 and ARID1A was observed in PILC than previously reported in classic ILC [239].